When you install Adblock Plus, you may get a notification that reads something like "This extension can see, read, and change EVERYTHING!" Well, maybe not that dramatic, but those messages can be a bit scary and rightfully so. You should be aware of what extensions can do.
The permissions being requested are what is offered by the supported browsers. Adblock Plus only uses the permissions necessary for ad blocking. You will find more details below.
To understand this permission, it’s important to know that ad blockers work by first blocking a web page's requests to download ads from the servers that host them. Secondly, by hiding any ads that can't be blocked.
To do that, the extension needs to:
- See every page you open so that Adblock Plus can work on every page you visit. This also means that Adblock Plus knows the URL of every page you visit.
- See all the data on the page to find any unblocked ads among the other content. This also means that Adblock Plus can see any forms you submit and your browsing activity on that tab.
Granting "Webpage Contents" permission (Safari) allows ad blockers (all ad blockers in general) to hide ads if they can't be blocked.