I think it's fine if the LJ user didn't specifically say not to repost. Most of the ones I've seen say that if you repost, give credit. Credit should always be given anyway. THIS MEANS YOU, KIDDIES.

I don't mind occasional LJ icons. But when it's all someone posts... what's the point? Make something of your own!

No if they say: don't repost.
Yes if you give credit
XD

I don't see the problem in posting them, as long as they are credited and the creator doesn't mind.

Usually it's fine as long as you credit.
If I'm not sure whether a user is ok with me posting here, I usually ask them before uploading them.
Occasionally I make my own though so I upload those when I come out of my bubble of laziness XD

As long as it's ok with the creator to repost it.

Depends.
I don't think it's okay WITHOUT consent. It's their work and we should respect what they want people to do with it, if the graphic makers say it's okay as long as you give credit, then fine. But otherwise I don't think we should.

But I don't do it anymore.

What's with LJ specifically though?

I don't know. I've seen a few images on Deviantart with "do not repost/copy" messages, but that website doesn't have the reputation LJ does.

And as long as they haven't got "don't repost elsewhere" or "don't add to Fanpop" on their page.