I paid for a full retail version of McAfee and also Kaspersky and so far I am happy with the result, but I still think most of these Anti-virus companies are up to no good behind the scene.
Free or full version, I don't think it really affects the way they handle user data, it doesn't explicitly state that the data of users who have a paid version will not be passed on to third parties. Also when installing such programs the user is always ask to share some data with the company in order to improve products and combat virus/malware, and there is always an option to turn it off.
Im linux user, I have moved from Windows to Linux for 3 months, and now im loove with linux, everything is smooth and im never see any dangerous activity...
I think people rely too much on the fact that using
Linux OS means absolute security, the fact that you don't see "any dangerous activity" does not mean that it does not occur in the background without any indication of it. Linux is not immune to viruses/malware, but there are far fewer such threats than on Windows OS. And as I mentioned in a previous post, not only software or OS spies on you, hardware may also do it - and this is something only a few can discover.
Check this article :
For $2 you can put a HIDDEN SPY CHIP on any PC hardware