I remember a few years back, there was a "report" from someone that was at a tournament at some indoor warehouse like building. There was even some video's, wish I had saved them, one that showed a birds eye view of a game in progress when a bunch of German officers in SWAT/riot type gear come busting in, in the middle of a game, with their firearms drawn and pointed at anyone and everyone. There was another video, outside, showing offers milling around, and I think that a number of paintballers sitting on the sidewalk, just chatting, while being "guarded". The video's were up for a while, then disappeared
I know that Germany, at least, depends less on FPS for maximum velocity of a paintball, and more of what the Joules energy of the impact is, to determine how fast the paintballs can fly. From something said, but I can't verify if this is fully accurate, even if a marker is shooting at a specific velocity to assure that they are hitting at the prescribed Joules, if it has a regulator that can allow the velocity to go higher, then it could be considered illegal.