A sufficiently detailed record of a person's behavior could be used to fully reconstruct their psychology. This might constitute a form of immortality, but even if it doesn't, complete knowledge of the past would be a beautiful thing to have, it would make the future richer to know its past and to be able to bring back faithful replicas of the people who built it.
So this is an important question. To produce sufficiently detailed records... is that already happening by default? Is the ad industry already keeping all of that stuff? Will it all eventually make its way to light?
I've been assuming it's happening. Storage is cheap. The data has lots of buyers.
If not, then I'm going to need to start recording and backing stuff up more thoroughly.
I don't really know, but as I understand it, there are laws in Europe preventing companies from keeping data indefinitely. Also, ad companies might just be keeping the extracted insights they need. Downloading your chat logs seems really cheap, so seems to me worth the marginal cost in any case.
By the way, you might be interested in Lifelogging as life extension for more content on this topic.