Who were the protesters that broke into buildings on Capitol Hill after attending a rally in support of Donald Trump?
Some were carrying symbols and flags strongly associated with particular ideas and factions, but in practice many of the members and their causes overlap.
QAnon among the protesters
Images show individuals associated with a range extreme and far-right groups and supporters of fringe online conspiracy theories, many of whom have long been active online and at pro-Trump rallies.
One of the most startling images, quickly shared across social media, shows a man dressed with a painted face, fur hat and horns, holding an American flag.
He's been identified as Jake Angeli, a well-known supporter of the baseless conspiracy theory QAnon . He calls himself the QAnon Shaman.
His social media presence shows him attending multiple QAnon events and posting YouTube videos about deep state conspiracies.
He was pictured in November making a speech in Phoenix, Arizona, about unproven claims the election was fraudulent.
His personal Facebook page is filled with images and memes relating to all sorts of extreme ideas and conspiracy theories.
The Proud Boys
Another group spotted at the storming of the Capitol were members of the far-right group Proud Boys.
The organisation was founded in 2016 and is anti-immigrant and all male. In the first US presidential debate President Trump in response to a question about white supremacists and militias said: "Proud Boys - stand back and stand by."
The individual on the right is Nick Ochs, who describes himself as a "Proud Boy Elder".
One of their members, Nick Ochs, tweeted a selfie inside the building saying "Hello from the Capital lol". He also filmed a live stream inside.
We haven't identified the individual standing on the left in the above image.
Mr Ochs profile on the messaging app Telegram describes himself as a "Proud Boy Elder from Hawaii."
Individuals with large followings online were also spotted at the protests.
Among them was the social media personality Tim Gionet, who goes under the pseudonym "Baked Alaska".
Tim Gionet, better known as "Baked Alaska", livestreamed himself from the Capitol on Wednesday
His livestream from inside the Capitol posted on a niche streaming service was watched by thousands of people and showed him talking to other protesters.
A Trump supporter, Mr Gionet has made a name for himself as an internet troll.
He's been described by the Southern Poverty Law Centre, a US nonprofit legal advocacy group, as a "white nationalist", a label he disputed in a comment to The Insider .
YouTube banned his channel in October after he posted videos of himself harassing shop workers and refusing to wear a face-mask during the coronavirus pandemic.
Other platforms that have previously shut down his accounts include Twitter and PayPal.
Who wrote Nancy Pelosi a note?
A photo that went viral of a man who'd entered the office of senior Democrat politician Nancy Pelosi has been named as Richard Barnett from Arkansas.
Richard Barnett left a message for US House Speaker Nancy Pelosi saying "we will not back down"
Outside Capitol Hill buildings, he told the New York Times that he took an envelope from the speaker's office and says left a note calling her an expletive.
Reacting to the New York Times interview, Republican congressman Steve Womack said on Twitter: "I'm sickened to learn that the below actions were perpetrated by a constituent."
Local media reports say Mr Barnett is involved in a group that supports gun rights, and that he was interviewed at a 'Stop the Steal' rally following the presidential election - a movement that refused to accept Joe Biden's victory and supports the president's unsubstantiated claims of electoral fraud.
In the interview at the rally organised by 'Engaged Patriots' he said: "If you don't like it, send somebody out to get me 'cause I ain't going down easy."
The group associated with Mr Barnett held a fundraiser in October with proceeds going towards body cameras for the local police department, according to the Westside Eagle Observer local paper.
Reporting by Jack Goodman, Christopher Giles, Olga Robinson and Shayan Sardarizadeh.
A protester wearing a shirt with the QAnon slogan 'Trust the plan' talks to police inside the US Capitol building on Wednesday
Supporters of the QAnon movement were among the crowd that stormed the US Capitol building on Wednesday.
Several prominent activists were spotted inside the building, and others flew Q-themed banners inside and out.
President Trump - viewed as a hero by the movement - has stopped short of endorsing the conspiracy theory but has described QAnon activists as "people who love our country."
So what is QAnon and who believes in it?
What is it?
At its heart, QAnon is a wide-ranging, completely unfounded theory that says that President Trump is waging a secret war against elite Satan-worshipping paedophiles in government, business and the media.
QAnon believers have speculated that this fight will lead to a day of reckoning where prominent people such as former presidential candidate Hillary Clinton will be arrested and executed.
That's the basic story, but there are so many offshoots, detours and internal debates that the total list of QAnon claims is enormous - and often contradictory. Adherents draw in news events, historical facts and numerology to develop their own far-fetched conclusions.
Where did it all start?
In October 2017, an anonymous user put a series of posts on the message board 4chan. The user signed off as "Q" and claimed to have a level of US security approval known as "Q clearance".
These messages became known as "Q drops" or "breadcrumbs", often written in cryptic language peppered with slogans, pledges and pro-Trump themes.
"Where we go one we go all", often abbreviated as "WWG1WGA!" is one of the most popular QAnon slogans
Nobody actually believes it, right?
Actually, thousands do. The amount of traffic to mainstream social networking sites like Facebook, Twitter, Reddit and YouTube has exploded since 2017, and indications are the numbers have gone up further during the coronavirus pandemic.
The big social media companies subsequently tightened their rules about QAnon content and took down hundreds of Q-supporting accounts and videos.
But social media and opinion polls indicate there are at least hundreds of thousands, if not millions, of people who believe in at least some of the bizarre theories offered up by QAnon.
And its popularity hasn't been diminished by events which would seem to debunk the whole thing. For instance, early Q drops focused on the investigation by special prosecutor Robert Mueller.
QAnon supporters claimed Mr Mueller's inquiry into Russian interference in the 2016 US election was really an elaborate cover story for an investigation into paedophiles. When it concluded with no such bombshell revelation, the attention of the conspiracy theorists drifted elsewhere.
True believers contend deliberate misinformation is sown into Q's messages - in their minds making the conspiracy theory impossible to disprove.
QAnon supporters bring banners and flags to rallies in support of President Trump
What impact has it had?
QAnon supporters drive hashtags and co-ordinate abuse of perceived enemies - the politicians, celebrities and journalists who they believe are covering up for paedophiles.
It's not just threatening messages online. Twitter says it took action against QAnon because of the potential for "offline harm".
Several QAnon believers have been arrested after making threats or taking offline action.
In one notable case in 2018, a heavily armed man blocked a bridge over the Hoover Dam. Matthew Wright later pleaded guilty to a terrorism charge.
A Pew Research Center study in September 2020 found that nearly half of Americans had heard of QAnon- double the number from six months before. Of those who had heard about it, a fifth had a positive view of the movement.
And for many believers, QAnon forms the foundation of their support for President Trump.
Mr Trump has, unwittingly or not, retweeted QAnon supporters, and prior to the election his son Eric Trump posted a QAnon meme on Instagram.
One outspoken QAnon supporter, Marjorie Taylor Greene of Georgia, was elected to the US Congress in November.
With additional reporting by Jack Goodman and Shayan Sardarizadeh
President Trump mentioned a far-right group during the first presidential debate, kicking off online celebrations by its supporters.
"Proud Boys - stand back and stand by," he said, in a response to a question asking him to condemn white supremacist and militia groups. Members of the group online took the answer as a call to prepare for action.
Mr Trump then insisted that violence was coming from far-left activists: "Somebody's got to do something about antifa and the left, because this is not a right-wing problem."
Joe Biden, the Democratic challenger, answered back: "Antifa is an idea, not an organisation. That is what [President Trump's] FBI director said."
Over the past few years, a number of fringe groups have been engaged in politically motivated violence on American streets. So who are Proud Boys and antifa?
Founded in 2016 by Canadian-British right-wing activist Gavin McInnes, the Proud Boys is a far-right, anti-immigrant, all-male group with a history of street violence against its left-wing opponents.
The group's name is a reference to a song from the musical version of the Disney film Aladdin. Members often wear black and yellow Fred Perry polo shirts along with red "Make America Great Again" hats.
A Proud Boy with an "Antifa hunting permit" sticker on his helmet
A Proud Boy must declare that he is "a Western chauvinist who refuses to apologise for creating the modern world".
Their platform, such as it is, includes Trumpian ideas ( "glorify the entrepreneur", "close the border" ) libertarianism ( "give everyone a gun", "end welfare" ) and traditional gender roles ( "venerate the housewife" ).
They're not exclusively white - yet have became notorious for violent political confrontations.
The Proud Boys and affiliated groups have faced off against antifa in a number of violent street rallies in the last two years, most notably in Oregon, Washington and New York. Two members were jailed last year for beating up antifa activists in New York.
Facebook, Instagram, Twitter and YouTube have all banned the group from their platforms, and members and official chapters have been largely shunted towards less-popular networks.
Enrique Tarrio, the group's current chairman, reacted to the debate on the alternative discussion network Parler: "Standing by sir.... I will stand down sir!!!"
McInnes publicly disassociated himself from the group in 2018, saying that he was taking the advice of his legal team.
But in a video reacting to Tuesday's debate, he said (albeit not seeming entirely serious): "I control the Proud Boys, Donald. Do not stand down, do not stand back."
On the chat app Telegram, Proud Boys shared the debate clip along with posts taunting antifa and incorporating the phrase "stand back, stand by" into the group's logo.
Meanwhile, critics of the president loudly condemned him.
Antifa, short for "anti-fascist", is a loose affiliation of mostly far-left activists.
They include anarchists, but also communists and a few social democrats. What sets them apart is their willingness to use violence - in self-defence, they say.
The movement, which at one point almost entirely disappeared in the US, saw a surge of interest after the election of Donald Trump. They routinely clash with the far right.
The group has been prominent during Black Lives Matter protests in many major cities, and have been particularly associated with unrest in Portland, Oregon.
In late August, a self-described anti-fascist, 48-year-old Michael Reinoehl, shot and killed a supporter of Patriot Prayer, a Portland-area group that often marches with the Proud Boys.
Reinoehl was shot dead by police the following week.
Both groups are relatively small - and can count on, at the most, a few thousand active supporters. But their propensity for violence, particularly when they confront each other on American streets, has made them a much bigger topic of conversation than those numbers suggest.