When commenting, and you write a URL in backticks, the
http://www. part is cut off, and it is converted to a link. Converting it to a link might not be so bad, but cutting it off can change the meaning of the content as you usually put code in backticks.
I also accidentally came across a bug; there seems to be something strange going on with the characters after the URL. See my comments to this post. I entered the following in backticks:
See more bugs in comments to this question.