Change your passwords. And he's not in your system.
If you've heard that he's trying to track your internet activity, then he isn't at the present time. Anyone who is dumb enough to say that he would try is also dumb enough to brag a bit if he were.
So if he's not, as seems clear, and he's locked out of the systems, an added layer of protection for you would be to change your passwords.
If he's not locked out of the system, then he would already be doing it. But the system settings could be changed so as to lock him out.
Yer safe.
Arf