Do you have a link?
Fortunately this one was a false alarm : the poster said it's just the janitor's union. I have a sneaking suspicion , though, that there may be some efforts to 'drum up" protests-we shall see if there are and if it works, over the next few days. I predict if they try this, they'll schedule major marches for July 4th, and try to present themselves as "ordinary immigrants-and if you disagree, that' makes you racist". If they do, it could very easily backfire.