Okay, could happen I guess. How is the leadership chosen? I mean, over here it's always elections by members, so it prevent that kind of **it. What kind of benefit are you talking about?
I would have to read up on the former. As for the latter, mostly synecures.
Firt, unions are smaller than nations, so democracy works better, plus the spectrum of issue in union politics is smaller, so you can't use diversionary tactics about THEM GAYS BRAKE OUR WEATHER!! or something.
Over here, I wouldn't be so sure. Poland is, as far as the ideology of average Joe goes, waaaay backwards. In particular, attempts to introduce the idea that being TEH GHEY =/= being an avatar of Satan Hitler has met with tremendous resistance and media, government and Catholic Church, in inverse order chronologically, claiming it's sexualizing children (basically the ol' GAYS ARE PEDOPHILES! hysteria).
Speaking of which, the major unions have allied, and a significant part of their membership supports, the major opposition party which is pretty much the ideological antithesis of mine (socially conservative, Christian, quasi-nationalist (not outright, but they are supported by outright neo-Nazis)).
I wouldn't classify strikes under intimidation or violence, but anyway...
I don't particularly mind strikes, but I've heard a union call for the boycott of a company
where their members were working lately - that actually harms each employee more than the employer. Or things like lock-ins - I consider that, for all instances and purposes, an act of kidnapping.