Tolerance of Intolerance?

One of the central understandings I carry about the Gospel of Jesus is one of love and tolerance. I believe we should always be tolerant of others views, opinions and religious beliefs or non beliefs. I feel we should protect those beliefs as well. I like to see myself as a very tolerant person striving to accept those who are different than me. Lately I have come across a flaw in my understanding of self, as well as my theology of tolerance. I wonder if I am intolerant of those who are intolerant? I find myself not tolerating them because they infringe on others ability to believe without harassment. By the way this has nothing to do with the Emergent No conversations, I have been thinking about this post for several months. So I do not know what to do. Do I help protect others beliefs by being intolerant of those who are intolerant? I do not think I can do that because it then becomes a circular argument and I then carry the exact same premise as those who I am being intolerant of. This is a real mental block for me, any ideas?
Pax
Stephen