I thought wearing masks was illegal.
"United States
There are anti-mask laws in many U.S. states and the District of Columbia.[1]
New York State's anti-mask law was enacted in 1845, to provide for public safety after disputes between landlords and tenants.[2]
Many anti-mask laws date back to the mid-20th century, when states and municipalities passed them to stop the violent activities of the Ku Klux Klan, whose members typically wore hoods of white linen to conceal their identities.[3][4]
In the 21st century those laws have been applied to political protesters such as those affiliated with the Occupy Movement or Anonymous – wearing Guy Fawkes masks.[5][6][7][8]
In some areas motorcyclists have been arrested using anti-masking laws.[9]
These laws have been challenged on the grounds that they violate the guarantees of the First Amendment to the United States Constitution to free speech and free association. Some courts have weighed freedom of speech against the public safety interest, and upheld such laws. For example, the Georgia Supreme Court found the law constitutional on the grounds that the wearing of the mask was an act of intimidation and a threat of violence, which is not protected speech.[10] That law has exceptions for holiday celebrations, theatre performances, and occupational safety; the ruling makes it unclear if someone is violating the law if they wear a mask without the intent to threaten violence. A three-judge panel of the United States Court of Appeals for the Second Circuit upheld a New York law on the ground that wearing a Ku Klux Klan mask did not convey a protected message beyond that conveyed by wearing a hood and robe.[2] Other courts have struck down anti-mask laws. For example, Tennessee and Florida state laws have been invalidated on the grounds that they were unconstitutionally broad.[10] An ordinance in Goshen, Indiana, was struck down based on First Amendment doctrine that specifically protects anonymous speech and anonymous association, especially for unpopular groups like the KKK.[2]
During the 1918 influenza pandemic in San Francisco, California, a group of citizens that included doctors and several city supervisors formed an "Anti-Mask League" after becoming frustrated with mandated mask-wearing."
https://en.wikipedia.org/wiki/Anti-mask_law#United_States