And if O2's apparent U-turn on the subject wasn't awkward enough, Three's owner is in the process of acquiring the rival carrier. While that's far from a done deal, it could make for some frigid boardroom meetings, considering the networks' conflicting stances. It's important to note that Three won't block all ads at the network level, just those deemed intrusive, irrelevant or malware-ridden. O2 isn't a fan of those types of ads, either, but Dunne prefers a more passive approach, encouraging advertisers to commit to the Internet Advertising Bureau's guidelines on responsible ads.

Call it conflict of interest or industry insight, but O2 runs its own advertising platform, called Weve, which is doing quite well for itself, if last year's revenue growth is any indication. Online advertising is one of those necessary evils: It keeps websites afloat and mobile games free. But you need only look at the growing acceptance of ad-blocking tech among huge device makers like Apple and Samsung to see that there's an appetite for a leaner web. Circumventing ad blockers is a business now, too. Companies have taken to paying their way onto whitelists already, so perhaps O2 will pull another 180 if it concludes there's any money to be made.