just wondering what some of those in the US (and maybe Canada) think about what seems what seems to be an overly aggressive response from the left on subjects that offend them or not agree with? I have heard of a lot of it happening on university campuses.
Heard from whom? I've studied or taught at about seven different colleges across two states and seen very little evidence. Arguably the most prominent example of an aggressive response to offense was driving Ward Churchill out at CU-Boulder (which was driven more from the right than the left, though I concurred with that particular move and acted in my official capacity on the student union to block that group from resolving in support of Churchill.
Maybe at a few elite liberal arts schools and Cal-Berkeley there is some hyper-liberal policing but that is a small fraction of the student population, even though the media acts like it is all that exists.