I am working in the adtech industry and can say as a fact that all data is anonymous. Anonymity is very seriously enforced throughout the industry and, additionally, lack of such anonymity will be seen very quickly by huge amounts of engineers working with user databases.
Which is exactly why I am asking Will what exactly he is afraid of. The need to run off of LinkedIn, scrambling information about oneself, because Microsoft buys it, shows irrational hatred for Microsoft that is probably ideologically charged. And probably hints at all the free software alarmist propaganda about how "corporations are controlling you", which is in the vast majority of cases is simply misrepresentation of actual state of things.