People conceal their identities from police and media during demonstrations for many different reasons: school, employment, immigration status, Child Protective Services, right-wing vigilantes. Even if you do not engage in confrontational actions, masking up can protect the autonomy of those who do. The more masked people there are, the safer are those who are most likely to be targeted by the police. Together, we have tremendous power.
Regardless of your feelings on whether or not confrontation with the cops is tactically sound, the long history of state repression in this country conclusively demonstrates that the state will mobilize all of its power to crush any movement, peaceful or not, that poses a real threat to its hegemony. You can be sure that the police are filming during any large demonstration and moment of revolt, in addition to monitoring the feeds of those livestreaming. Those who do not have their faces covered, even if they are acting within the law, are much more likely to have attention paid to them in the future.
Directions
Bring multiple layers: one outfit to get into the area, another for the action, and something that will help you blend in when it’s time to make your exit. Take out piercings; conceal tattoos. Some people choose to wear identical clothing—black hooded sweatshirts, pants, and masks—in order to be indistinguishable. Use your discretion for if this makes sense for what you’re trying to do. If you choose to do it, make sure your clothes have no identifying features. Your shoes or backpack could also identify you.
To cover your face, get a t-shirt and turn it inside out. Simply put it around your head as if you were putting it on, put your face up to the collar ring, but don’t push your head through it. (see above image) Tie the sleeves together behind your head to tighten the mask, and then pull the bottom of the collar up to just below your eyes, covering as much as possible. Combine with a hoodie and sunglasses to completely cover your face, but beware that glasses could fog up due to your breath. You should practice at home first to get the hang of putting it on quickly.
(Thanks to the folks behind Nightfall and Crimethinc for pieces of this)