General Discussion

Carry bottled water with you to wash your eyes if maced/teargassed.
A backpack with a book inside worn in front instead of on your back as makeshift body armor against rubber bullets.
The kind of respirator used by painters.
I've also wondered whether it would be better to bring an easily-hidden gopro or other small video camera than your own cell phone, which could be confiscated (along with a lot of personal information). Get a burner phone for calls and texts, use the gopro for video, leave your personal cell phone at home where it's safe. ICE is also less likely to notice that you are recording if you aren't holding up a phone.