In many US states and the District of Columbia, there are anti-mask laws.

Anti-mask laws date back to the mid-20th century when states and municipalities passed them as to inhibit the Ku Klux Klan, whose members typically wore hoods of white linen to conceal their identities.

In current times, masked political protesters such as those affiliated with the Occupy Movement or Anonymous—a collective group of online hackers with strong political beliefs who consistently wear Guy Fawkes masks—have been targeted with anti-masking laws.

I will be citing a felony code enacted by the State of Virginia which bans any form of masking in public:

§ 18.2-422. Prohibition of wearing of masks in certain places; exceptions.
It shall be unlawful for any person over 16 years of age to, with the intent to conceal his identity, wear any mask, hood or other device[b] whereby a substantial portion of the face is hidden or covered so as to conceal the identity of the wearer[/b], to be or appear in any public place, or upon any private property in this Commonwealth without first having obtained from the owner or tenant thereof consent to do so in writing.
However, the provisions of this section shall not apply to persons
(i) wearing traditional holiday costumes;
(ii) engaged in professions, trades, employment or other activities and wearing protective masks which are deemed necessary for the physical safety of the wearer or other persons;
(iii) engaged in any bona fide theatrical production or masquerade ball; or
(iv) wearing a mask, hood or other device for bona fide medical reasons upon (a) the advice of a licensed physician or osteopath and carrying on his person an affidavit from the physician or osteopath specifying the medical necessity for wearing the device and the date on which the wearing of the device will no longer be necessary and providing a brief description of the device, or (b) the declaration of a disaster or state of emergency by the Governor in response to a public health emergency where the emergency declaration expressly waives this section, defines the mask appropriate for the emergency, and provides for the duration of the waiver. The violation of any provisions of this section is a Class 6 felony.
http://law.lis.virginia.gov/vacode/title18.2/chapter9/section18.2-422/

As can be seen from this law, there is no room whatsoever for Muslim women to wear their bukhars! If they insist on going full sharia then they risk being arrested, their hijabs yanked off for a mug shot and thrown in jail.