Thinking through all the possible consequences of an action, business or personal, is hard. It's easy to be so focused on the outcomes that we want, that we can lose sight of the outcomes that are probable, or even just possible.
Feelings are experienced. There is no need to apologize to companies like Facebook and Twitter. These para-sites rely on everyone over-sharing their lives so that companies that gamble on your identity (insurers), database marketeers, advertisement proliferators, and quasi-civilian police officers everywhere get what they need with less work and less judicial review.
Why apologize for doing exactly what Facebook wants you to do? They people that made that bed should be required to lie in it.
I doubt any of you have the inclination to watch this talk, but it's a great, semi-related talk on bad design. Yes they are companies. But the decisions are made by individuals and teams of people at those companies. Much more human than you might imagine.