Not saying this is the case, but it occurs to me... that would be a good way to sabotage the start of an union. Just send some aggressive people posing like members of the union.
It is, and there's evidence that has happened in the US.
The Pinkertons have been busting unions for over a century - they have pretty much explored the full range of options for worker suppression available to capital.
False flags can be a powerful tool (but becoming less so, as surveillance makes deniability harder).
