You're welcome to request your data from Facebook and see if they have this data (assuming they are following the law, which I assume they are). I've requested my data from various companies and they did not have anything even close to this level of detail. That makes me think that if they do store data such as keystrokes or mouse clicks or whatever, it's being stored in a highly aggregated way, which doesn't bother me very much. But I also imagine one of the reasons they are storing data in an aggregated way is: 1) they don't need it at an individual level and/or 2) it's not cost effective.