I honestly think this is OK for the time being. If I'm getting something for free, why not help the company too? This is why I actually display YouTube ads nowadays, and I can't seem to find anything too absurd about them. I'm also using my Youtube account Better support Google then Facebook. Disclaimer: I don't use GMail, just YouTube. My Google account help me sort things out.
Client side data stripping. For example, malware detected in: C:\Users\RejZoR\Local\Desktop\malware.exe This string is stripped of user identifiers on user's PC before it's sent to AV vendor cloud and what vendor receives is: C:\Users\USERNAME\Local\Desktop\malware.exe or C:\Users\UNIQUE_USER_ID\Local\Desktop\malware.exe In order to keep context while not really knowing what user was that. Sure technically you could dig it out who that was, but in a way they need such behavior in order to know when same system has been getting different infections in the same location. This is just one of more obvious examples, but it would be nice if you'd actually know what specifically they collect and how they strip the dataw ith such before and after examples. And then you have to trust them they are actually doing this. Some may receive full data and stripp it server side at the entry point so they get the full data, but you have to trust them again that they actually strip the data before it's further processed.
