And they've taken off too. For the first few days after iOS 9 was released ad blockers dominated the App Store charts.

We've been working with one of our clients to try to detect how many users are currently blocking advertisements online. On Desktop we're seeing about 30% of their traffic block ads and currently on mobile there's 1% of users blocking ads.

Many of these new content blockers aren't just ad blockers. They can block comment systems, share buttons and custom web fonts. That might make sites look and work a bit different than we wanted, but probably would be fine.

The real problem is this: many content blockers also block trackers. Trackers like Google Analytics.

Without trackers we can't understand how people use the site. We can't track how many people block ads; so how can we know how to provide better ads that users like? We can't track page interactions well; so how can we know what kind of content people like?

There perhaps is a valid debate to block ads on mobile if they're sucking up 3G bandwidth and costing users money. Maybe. It's still stealing, but it's probably done so out of frustration from bad user experience with popup ads and autoplaying video takeovers.

But blocking anonymous tracking tools for website analytics? Bonkers.