all in one place for you
BLM: black lives matter - protests against the death of George Floyd.
Upside down: distress symbol. historically used for ships, in modern context it's used as a symbol of protest against government and injustice.
Gatsden (don't tread on me): originated in the civil war, stands for liberty and freedom against oppression. Today it's mostly used by people who want a smaller, less active government
AIM: American Indian Movement. Better treatment for Indians, especially those in cities and stuff