By “on the clock” I mean during compensated scheduled working hours. It does not matter if you are an hourly or salaried employee. They were removed and charged with trespassing after multiple warnings from security, and warned in advance of the policy violation of the protest according to this employee interview.

You are protected by law if protesting working conditions or compensation during scheduled working hours. If you protesting anything else, it can be done during free time in a public space without employer retaliation.

I have been part of many protests, and am in complete support of them. The most important thing when organizing a protest is knowing your rights so you can keep the law on your side.