These are far from guarded comments. Back in May, the Financial Times reported that "several" carriers were planning to block advertising on their networks. It said one European operator was already installing the necessary software in its data centres and would be ready to switch it on this year. None of the UK's major networks have commented on the issue until now, however. Business Insider quotes Franks as saying that O2 is undergoing "proper testing" with some of its customers. That's in contrast to EE, which has merely launched an internal review about pursuing such technology.

Ad-blocking continues to grow in popularity. There are plenty of free desktop browser extensions and now, third-party iOS apps that will rip ads entirely from the web. They make browsing faster, cleaner and, according to Edward Snowden, more secure. The counterargument is that many businesses rely on advertising revenue to survive, and blocking everything is a sure-fire way to put them under. Some users "whitelist" sites that have adopted ads tastefully -- a mechanism to promote better designed and targeted web ads -- but it's not clear how prolific this is among the ad blocking community.

The practise is still niche, especially on mobile. But if EE and O2 were to offer such a service, it could have a huge knock-on effect for companies that run large advertising networks. EE and O2 are framing the technology as pro-consumer -- a way to improve the web experience for their customers -- but it could also be a way to bolster their profit margins. The theory goes that carriers could use the technology to hold advertisers to ransom; pay up, or your ads will disappear from customers' smartphones. Amazon, Google and Microsoft reportedly cut a similar deal with Adblock Plus earlier this year. The real question is whether O2 and EE are alone in their ad blocking deliberations -- if Vodafone, Three and others are doing the same, we could be on the verge of a power struggle.