I am pretty much the same. I trust everyone, it is only when they give me reasons to doubt them that I become suspicious, whether offline or not. People can lie to you either way, the difference with online is that you cannot see their face.
That being said, I always believe in the best in people, whether or not they deserve it. Sure, it might open me up to pain, getting hurt or other problems, but that is something I realize. I would not be me, if I did not believe in people. It is simply how I am and I do not regret it.