I've often been offended by views expressed by persons of a different opinion, and so has everyone else. I do not get violent towards them, though I may attempt to make them see just how they are wrong - verbally, and without insults (well, as much as possible). The most sensitive people on this island must be some of the Northern unionists - and they're generally quite happy to deal out insults to those who differ from them. I'm thinking Paisley.
However, Fintan O'Toole made a good point in his Irish Times article on this. He said that, as I remember, the degree of sensitivity reflects self-esteem. That in the 70s and 80s we would all have been incensed by the portrayal of the Irish by the drunken-leprachaun stereotype and now we just laugh at it, as reflectiing the ignorance of others.
BTW, the Muslim demo in Dublin seemed a small and good humoured affair, even if the protesters were nearly outnumbered by their accompanying gardai.