Perhaps you should impose file upload limits (pic size)...
Actually I do. I have the system resize any oversize image in a thread post down to 1000 x 750 pixels. That way the picture fits just nicely on anyone's screen where there resolution is set to 1024 x 768 or higher.
You wont find any pictures in the posts that are bigger than that. I've been doing that for years now. On very rare occassions the Image Resizer fails and you get a larger picture, but that is extremely rare.
Most other sites like Facebook and the like resize pictures down to much less than 1000 x 750 pix, but that is one of the unique things about this site. We like to see our agitators in big size so we can make out the fine details.
ps I do allow full size profile pictures, but you have to actually click on the profile picture for the full size to load.