The fingerprinting issue has been licked elsewhere. When a company like Tineye, which is a tiny fraction the size of PhotoBucket and Fox can do very good fingerpriting, even when images are editied, it defeats that argument. See also PicScout for this one.

Firstly the printing issue, while I feel your pain I would note that a modern colour laser eg:
http://www.lexmark.com/lexmark/product/home/108...
is very cheap and able to produce prints that an untrained eye will not be able to distinguish from professional prints. And a print that is “good enough” can often be produced from almost any inkjet printer.
Because of this I would say a better solution to this issue would be notification, so the uploader is notified if the image is passed (directly) to the printing option. They can obviously do nothing about indirect or local printing.

As for fingerprinting, Marcus said it a year ago, it's silly, just because something exists for video does not mean that the same technique will be effective for a still image. The simplest reason is that it's a lot easier to do a minor edit to an image than it is to a video.