“Google issued a stern warning to its employees, with the company’s vice president of global security, Chris Rackow, saying, “If you’re one of the few who are tempted to think we’re going to overlook conduct that violates our policies, think again,” according to an internal memo obtained by CNBC.”
Please note that Germany has (compared to other EU members) quite strict and company-friendly protesting laws.
Such protests may be even considered as political protest (Politischer Streik) which makes them not illegal per se but could be illegal. https://www.bpb.de/themen/medien-journalismus/netzdebatte/219308/ein-bisschen-verboten-politischer-streik/
Yes, I don‘t think such protests would fall under the general protesting laws as they have nothing to do with your working conditions.