i think it depends on many circumstances....as for using a picture in your avatar, well that's been done by most everyone on here (not me
) whether it be cues, girls, animated gif's, etc......that don't bother me.....for post's it's nice to have permission but then again if the owner doesn't want the pics on the net he shouldn't have put them where they can be taken and used in the first place........as long as they're not being used to deceive or gain benefit from then i don't care. on the other hand if they were pics sent to you privately via email or something then permission is definitely required imo....