It depends what the pictures are. Are they of you? Are they of him? Are they of mutual friends? As long as the pictures aren't of other people doing things that they wouldn't want their mother to see, then I don't think you need permission first. You can ask for his permission first, but really if he put them on facebook then I think its ok to save them. If he really didn't want you to have them, then he wouldn't give you access to them (through facebook) in the first place. That's just my opinion though...

If you want to keep this person as a friend, ask permission.

No, u should ask him/her first !

I agree with Adelus.He should permit you to do so.