This is a great idea and is something similar to what I was thinking of implementing in the ad blocker that I develop. Some suggested improvements would be to

This is a great idea and is something similar to what I was thinking of implementing in the ad blocker that I develop. Some suggested improvements would be to actually use domain names ('*.google.com') as the way to classify filters instead of just tags ('google'). This would make it possible to integrate with an ad blocker that automatically suggest filters to enable when you are browsing a specific website. E.g. when you are browsing Google you could see the list of suggested filters you could enable for that site based upon the filters from letsblock.it It would also probably be necessary to add some rating or scoring of the filters in the future to sort and flag those which are most helpful vs. those which are out of date or no longer work.