I am thinking of recording my conversations to keep other accountable for what they say. I understand there’s some legal and ethical issues with this. But in principle, do you have similar motivation for quantified self? Or is quantified self strictly for self-improvement by learning from data you accumulate?
Indeed, there are legal aspects you should be aware of.
While I personally think that keeping others accountable for what they say falls outside of the scope of QS, I may take notes of what someone said, for my personal use (for example, quantifying my relationship with them). Also, when you communicate via means that are implicitly recordable, such as instant messaging, your copy of the communication can be freely mined for information (word tags, mood detection etc.)