Ha Ha - I see this is a real jar of worms here, but I am still sticking to my opinion - but respect those who feel different.
I have used UV or Skylight filters for years and never had anything negative to report from using them - only posative
and just as those of us who don't use them are sticking to our opinion and respect yours. I have not used any type of UV filter for protection for years either, and have not ever had a problem. In the event something does then I'll probably just send the lens to Canon and spend the $75-$100 and get the front piece of glass replaced.