I overheard two of my coworkers the other day talking about it and I actually ran into it myself the other day. What am I talking about? Its the common practice to use encode urls spaces as '-' when the standard says they should be '+'.
So these begs the question of, why do they do this?
My best guess, just because it looks better. I think search engines caught on and now will treat '-' as a space when they parse the urls for keywords, which is to bad for things that actually have a '-' in their keywords.