This same thing happened to me for putting up anti-war posters in 2002 when I was a grad student at UCSC. I was charged with felony property destruction via a “gang activity” enhancement. We got them to drop the charges but it took extensive organizing. https://twitter.com/thedailybeast/status/1291828291544985602

I was a member of an org called “POC Against The War” (in Afghanistan) and we put up over 200 posters on walls with wheat paste. I was told that if I gave the names of all the people in my “gang” they would reduce my charge to a misdemeanor. I told them to fuck themselves.

We organized protests, petition campaigns and letter writing campaigns demanding the DA drop the charges (one of the letter writers was my professor Angela Davis, so that helped!) it took 8 weeks but it worked. Charges dropped. Letter of apology from the DA.

TL;DR never cooperate with the police, and fight back!