To add to this, your questions are bizarre. What do I mean by ‘Facebook tracking individual user behavior’? Um... I don’t know what to say to that. What a stra

To add to this, your questions are bizarre. What do I mean by ‘Facebook tracking individual user behavior’? Um... I don’t know what to say to that. What a strange question. It’s pretty clear what is meant by that. It’s the primary focus of their business. Next, “usually when you train a model you extract features for each event and then you apply your model at prediction time”. That’s nice, but when did we start discussing ‘training models’? Facebook has a list of internet activity. It’s stored by user. They’re in the business of selling personal data. Nothing you said has anything to do with that. I have no idea what we are even discussing. Whether someone can make an ad hoc a query by user is completely not the point and has nothing to do with anything. I would assume that they have extracted the information into other reports or data stores, obviously, not process trillions of lines of entries whenever they want to access it by individual.