You don't need to unsub from them unless you've already chosen to allow them. By default, ALL major browsers block push notifications unless you click "allow" when your browser tells you that a site would like to send notifications. If you have clicked allow without meaning to, you can click the icons just to the left of the URL up at the very top of the browser window and revoke the permissions.
It's not nefarious. It's not sneaky. It's not pushy(other than in the literal technological sense). It's a feature that many people appreciate. One, that by default is disabled in every stock major browser for those that do not.
Well @schwim You are Not going to like this reply....
I went into my - Avtar / Account Settings / Preferences and found "ALL" of those "Push" things checked to ON.
I Never made that selection,,,,,, they are all set to OFF now...
just sharing this info as to not be "Nefarious" or anything.
Thanks @fullsize ....
I'm pretty sure some folks will be much less apt to speak / defend in the future.