While there obviously have not been any high profile instances of violence by Christian terrorists in Europe in recent decades, it certainly is not the case that Christians are universally peaceful and tolerant.
Briefly, as a teenager, I had an interest in neopaganism (which proved a brief detour along the road to atheism). There was a fairly large neopaganism chat forum, similar in structure to Mumsnet, which had various subforums - including regional ones. The moderator for my region became inactive, so I volunteered to step in (although, in practice, I never actually had to do anything).
Unfortunately though, being listed as a moderator led to me receiving abusive and threatening messages, including death threats, from people who identified themselves as Christians (which, from talking to the other mods, was not uncommon). There were never any resulting instances of physical violence, but the threats most certainly were not peaceful.
If it doesn't go without saying, I don't believe the abusers were representative of all, most, or even a significant minority of Christians, but there are some nutters out there.