Underscores in URLs break the link

http://a.com WORKS (i.e. produces a clickable link)

http://a_b.com WORKS

http://a_b_.com DOESN'T WORK

This is unfortunate since underscores are often used in URLs in place of a space. e.g. http://news.com/man_jumps_from_bridge

I realize this is probably because surrounding a word with underscores produces a _underlined_ word. However I've yet to see someone actually trying to do it on purpose. On the other hand I've seen (and posted myself) many such broken links. So perhaps we could get rid of the whole functionality since it causes so much grief with links and provides so little use.