I've uploaded a lot of my photos to facebook for friends to be able to see. Am I foolish to think that they shouldn't have rights to use my photos any way they want after I leave? Flickr is free. Does Flickr have rights to use people's photos even after they close their account?

Sometimes we do expect privacy, even in public. We're used to looking around to see if there are people watching us, but security cameras are often more difficult to detect. Furthermore we know that even if there are people watching us, there's no way for anyone who's not watching us at that particular second to see the things we do. I.E. for an action to be observed, an observer would have to be present in a rather narrow window of time and space. But when cameras are involved, a recording is made, which means anyone at any time and in any location in the future can view the recording. Security cameras allow for a potentially massive magnification of an event's persistence in time and space.

So it's more like riding a ski lift with a fake lift pass, or sneaking onto a subway without paying the fare, or telling your friends you aren't hungry when they split the cost of a pizza and waiting until they get full and eating the leftovers?

Exactly. Not spending money is sometimes effective in getting companies to change their actions, but spending money on things they do correctly is orders of magnitude more effective. iTunes Plus is great. Not only is there no DRM, but it's encoded at a much higher bitrate as well.