Obvious, real world example: I've been dreading Timeline because I know the only high-resolution pictures of me on Facebook (that I've either uploaded myself or been tagged in) all include my ex-girlfriend, so I'll need to take a different picture for the header image.

I know how absurd that may sound, but Timeline, especially taken long-scale, could have a major impact on how we perceive our lives and ourselves because of how impossible it will be to escape from the past without painstakingly filtering and removing posts and pictures.

The obvious response, of course: "if you don't want permanence, don't upload in the first place." And this will be something I keep in mind, unless Facebook adds features to easily prune content from Timeline. But it's ridiculous that I should need to be that concerned about every pithy status I decide to post, not because of its contents in the present, but how they could be perceived in the future by myself and others.