Is this in tournaments or just in practice matches?
Well, I have seen it mostly in league and club play. However, I believe the racking cheats aren't known by so many people over here and those who commit them don't talk about it. That's my impression, at least.
I haven't seen many arguments in major tournaments like in the US yet. This does not prove that there aren't issues, IMHO. I have a hunch that Europe is slightly behind in the rack cheating department. What I see most is pretty "clumsy" pattern racking against the opponent, RYO is not too common. I don't know if there is so much gapping. Hard to tell because usually you don't get to see other people's racks up close. I haven't played top players so I wouldn't know.