Walkie's freakout might have seemed over the top but I can see why someone would get angry if they clicked a legit thread at work and downloaded a porn image. Viewing music forums at work is obviously a no-no, but it's not likely to get you fired (unless that's all you're doing with your day), whereas downloading porn certainly will.
And the additional problem with spam posts and images in legit threads isn't just that it can get the viewer in trouble -- it tells the spam house that the page is getting views, and therefore attracts more spam. It also reveals the viewer's IP address to the spammer.
besides putting posting restrictions on newbies, I think it's also possible to restrict the ability of unknown lusers to post images at all. That would seem to be a good idea since embedded images can lead to a whole world of problems.
