[Bootwizard]

How do you know of your credentials are compromised?

[skyo]

Probably the best way to check is https://haveibeenpwned.com/

[dagurp]

Or https://monitor.firefox.com/ (which is basically the same thing)

[dylan604]

Check out your Recently Viewed/Watched category. If things you haven't watched yourself start to appear there, then chances are...