I strongly believe publishing something on the web involves commitment: you put the content online and have to stand by it, do not ever delete it, or if you must delete, then replace with redirects: deletion will break pages, links, references and cause problems to people who relied on you. Nothing is worse than erasing history.
So happened when, for unknown reasons, Yahoo deleted my flickr account, now even the embedded do not work any more, leading to a large scale breakage: my photography blog, which used flickr as an image source, is ruined, the large amount of work needed to fix it will incapacitate me for a good while. For this blog I think I may have to live with the breakage: trying to fix some old articles will confuse a number of aggregators. But the works part is, it break an unknown number of pages who used my content as intended, under CC-BY-SA, and break the legal ground of this use with the disappearance of the canonical source - and I feel really bad about this, by having no way to help those people, I feel like letting them down.
In an age when a lot of people are moving towards externally hosted services, I get myself traumatised by this experience and going to the opposite: what you have in your hand is holly, you can control and rely on it. All hosted services have a TOS allowing to remove your content at will. Do not depend on them for anything mission-critical.
But let's change the tone, look here:
This little guy is searching for a house, along with a ton of other not yet published images (some are just as innocent as it and some are the kind that if published here would bring me huge traffic, lots of page views, comments, Page Rank and some ad clicks).