Sadly the only people being hurt by this sort of protest are researchers that happen to use the same network (i.e. Bahnhof's own customers) and now are unable to access neither the legit website nor the pirate one.
And no, as a researcher you rarely have a choice to not publish in Elsevier ran journals and conferences when your university/department is evaluated (and funding assigned) based on number of publications in these venues. This is often imposed by the government, the uni and even less the individual researchers have pretty much zero say in it.
I have worked at a uni in Denmark where the government literally had lists of "approved" journals and conferences. If you have published there, you have got a score weighed by the importance of the publication. If you have published elsewhere, you got nothing and were effectively working for free because the university funding was directly tied to those scores.
For some fields this was pretty much a death sentence because the "approved" publications were either stuff where most people never manage to get a paper in (like Nature) or most of their usual conferences/journals were not on the list (a lot of humanities and arts where otherwise producing an artwork or composing a piece of music counts as a publication).