That's how the IMG tag has worked for... well.. a while now. The one caveat is that if the remote site is down, or the site reorganizes its content and the URL changes, the tag breaks. This is no big deal with quasi-ephemeral posts such as references to images in craigslist ads. But otherwise, to be certain, importing to your BF gallery will be a more stable way of presenting images here. Using your BF gallery also avoids potential issues with other members being on machines where a remote photo's location is blocked.