There are several safe-guards, with more to come. The biggest one that's coming is being able to unsubscribe directly from the notification pop-up itself. Thi

There are several safe-guards, with more to come. The biggest one that's coming is being able to unsubscribe directly from the notification pop-up itself. This will shut down abusers very quickly. Beyond that: -All notifications traverse GCM. Which means you've signed a ToS with Google and they can shut you down (also a little scary). -Opt-in must happen on the main page, or have the main pages "consent". This prevents iframed ads registering people, for example. -9/10 pushes must display a user visible element (that will have the unsub feature) which prevents people from being malicious on the background Service Worker thread. More will come as this feature develops and it's seen how things play out in the wild.