Ever gone to a site and tried to close the window/tab and instead of closing, you get a popup? “Wait! Don’t go yet! Come back and sign up to my email (legit spam) list!”.
It looks something like this:
And keep trying to get your ass outta there, and each time it gets more & more frustrating, because the site won’t let you close the damn window.
I don’t know about other browsers because I really don’t use any others.