An anonymous reader writes: Adblock Plus has been uninvited to the upcoming IAB Leadership Summit and is having its registration fee refunded. The company was informed of the cancellation in an email with little explanation. A company blog post reads in part: "Unfortunately, the top brass at the US IAB don't want us coming to their Leadership Summit next week in Palm Desert, California. We attended last year, and we signed up again for their 2016 meeting including paying the hefty entrance fee. We were fully confirmed and they even listed us on their website as a participant. Then this week we got one of those sudden emails that land in your inbox innocently, then floor you with something weird, unbelievable or ridiculous when you click on them. This one came from an unfamiliar IAB address, and it informed us that our registration for the summit was canceled and our fee refunded."