I stumbled across this absolute horror show yesterday.
One request to show me notifications, three modal windows, and two banners. (One of the banners is obscured by a modal.)
I think it’s time for Firefox to take a stand and block this insanity once and for all.
(Here’s a link to that page for anyone interested.)
I don’t mean to be a nuisance by resurrecting this thread, but this is the hill that I’m willing to die on. 
Firefox really needs to block these insufferable in-content pop-ups. It should have done it five years ago. If Firefox doesn’t address this issue first, I’m sure another browser will.
Firefox’s first killer feature was its pop-up blocker. Mozilla can do it again.
You can prevent Firefox from displaying prompts about accepting Notifications. There is a checkbox for that on the Settings page, use the Settings… button to the right of Notifications in the permissions section.
Enhanced Tracking Protection already blocks a number of the servers which deliver offers in pages, but if the offers are from a new server or the site itself, those typically are still allowed.
Fixing this is not trivial. A script in the page is modifying the visibility of various elements such as the dark translucent layer and whatever appears in front of it. But there is no obvious reason that pages shouldn’t be allowed to modify the visibility of elements. If you have used any ad blocking add-ons, you probably have noticed that they struggle to cleanly prevent this problem, sometimes leaving a dark layer with no close button (front-most content removed) or no scroll-bar (change to overflow properties not undone) or the page content invisible (change to opacity property or visibility property not undone).
Thanks for sharing your thoughts. That’s very interesting.
I agree it would be hard to block all of these pop-ups across the web. Still, I think it’s hard work worth doing. I think it would make the web much less annoying and would be an important differentiator for Firefox.
