Sites that detect ad-blocker usage have bigger problems to worry about, at least here in Europe.

I haven't seen this reported in the media yet but here is a Twitter message from privacy researcher Alexander Hanff with photos of an official letter confirming that detecting ad-blocker usage client-side is illegal in the EU. https://twitter.com/alexanderhanff/status/722861362607747072

Here's his initial message from yesterday, kicking off the thread: https://twitter.com/alexanderhanff/status/722506381451010048

I've got my popcorn ready and I'm waiting for what may be a very amusing discussion between publishers, advertisers, and lawyers in various European countries. Fascinating, regardless of which side of the debate you are on.