The thing that made me delete last month was when they reverted the email notification settings to default.It struck me that they were going to change things whenever they wanted and I had no power over my information whatsoever.

I can't say this sort of thing caused 6 million others to delete as well, but as someone who has had a Facebook account since 2004 this was the thing to finally push me over the edge.

I should add that I don't miss it at all.