Thanks for the info. I plan on making an IPA near the end of the summer and I probably won't use a bag, instead will filter the racking cane.
Although I'm not paranoid about bacteria, I wanted to believe it about not having to sanitize hops for dry hopping but I needed a better explanation. This is the closest to acceptable explanation I have found from http://www.winning-homebrew.com/dry-hopping.html
which adapts a 2003 BYO article:
"Many homebrewers are worried about contamination issues from adding un-sterilized hops to finished beer. This is unlikely because when the dry hops are added, near the end of fermentation, the alcohol helps keep any possible contamination to a minimum. Plus, since there are not many sugars left in the beer, there is not much for the beasties to eat. And finally, hops are anti-microbial and are therefore not a very good host for contaminants such as bacteria."
(EDIT: But is that the best explanation you have heard? I'm new so I can't rely on just my opinion)