Why is marijuana considered bad for you?

if you want some facts etc have a look here http://www.saferchoice.org/content/view/24/53/ some eyeopening stuff rite there

Wow this thread really caught up. No.... I don't think marijuana is harmful.
I do believe its not the best idea for athletes to be heavily smoking it all the time though because as we all know weed makes you lazy, and I HATE running while I'm high. All in all though,I think the benefits outweigh the harms. Legalizing it, I think would be the best choice for the government rather then going to war with us pot smokers. I mean seriously... it's a plant. It grows like evry other PLANT. Its like corn. It's a regular garden plant. If it were legal I would have it in my garden like every other vegetable and flower.