Ad blocking has been a massive talking point over the last 12 months and remains, arguably, the single largest issue faced by the mobile ad industry. Before we look back at the key developments in the world of ad blocking over the past year, a quick bit of scene-setting.

PageFair’s revised report says that, globally, at least 309m people are blocking ads on smartphones. This is backed up by a recent KPMG survey, of 2,000 UK households, which found that 49 per cent of consumers expect to adopt ad blockers in the next six months.

This creates a major problem for advertisers, but it is important to note that ad blocking has existed in various forms for the best part of 70 years. Changing radio station or TV channel, or fast-forwarding past the adverts to reach more of the zombie-based entertainment that was recorded on the DVR earlier, are all forms of ad blocking. Unlike those, though, on mobile and desktop a person can easily remove ads altogether without a second thought.

Ad blocking began on desktop in 2006, when AdBlock Plus started out as a Firefox browser extension – but it has only really come to mobile over the last couple of years. This has led to an ongoing tension between mobile advertisers, publishers and ad block providers in 2016.

IAB versus ad blockers
The Interactive Advertising Bureau (IAB) started 2016 with all guns blazing. In January, president and CEO Randall Rothenberg used his opening address at the IAB summit to accuse AdBlock Plus (ABP) of being an “unethical, immoral, mendacious coven of techie wannabes”, branding the company an “old-fashioned extortion racket”.

The IAB would continue its fight in March with the release of a Publisher Ad Blocking Primer pack – outlining tactics publishers are using to persuade users to stop deploying ad blockers. This pack included an ad blocking detection code for publishers to make use of.

On the other side of the Atlantic, the IAB UK also took up the fight, after Think Privacy CEO and privacy advocate Alexander Hanff in May threatened legal action against companies attempting to prevent ad blocking, telling Mobile Marketing that “people have the right to block ads… The people that are breaking the law are the publishers and the ad tech industry and the developers of the software that is doing this surveillance”. IAB UK CEO Guy Philipson hit back almost immediately, claiming Hanff took the “widest interpretation of the so-called ‘cookie law’”.

AdBlock Plus versus German publishers
The legality of ad blocking was very much at the forefront of the ad block agenda for much of the year, and did not just involve IABs. In 2016, ABP faced – and won – three lawsuits against German publications.

The first victory came in March, against Germany’s largest subscription daily newspaper Süddeutsche Zeitung. The case targeted the ad blocking company’s ‘Acceptable Ads’ program, which whitelists selected publishers based on certain criteria and, in the case of larger companies, whether they are willing to pay for it. The court ruled that users are not contractually obliged to view ads served by a publisher.

The second, versus publisher Axel Springer, followed in June. This victory, however, was less conclusive – the courts held that ABP should change how it offers whitelisting to Axel Springer. Thus, although ad blocking was again found to be legal, it was ruled that Axel Springer would be treated like a smaller business than it in fact is.

ABP’s final victory of the year occurred in November, when Spiegel Online – the online platform of one of Europe’s largest publications, Der Spiegel – took on the ad blockers. This time all claims were dismissed by the courts, bringing ABP’s victory total to six out of six versus German publications, having defeated Zeit Online and Handelsblatt, Prosieben/Sat 1 and RTL Interactive, and Axel Springer (for the first time) in 2015.

Publishers versus ad block users
2016 also saw publishers go after users for their ad block usage, opting for tactics of varying severity.

In February, Wired and The Independent followed the example that Forbes had set towards the end of 2015 – by preventing people using ad blockers from accessing their websites. In Wired’s case, it offered visitors a choice of either whitelisting the site or subscribing to an ad-free version for $1 a week (the New York Times explored a similar possibility in June).

Soon after, in March, Trinity Mirror and Telegraph Media Group would follow suit by trialing technology that locked out ad block-using visitors. In the same month, some of the biggest news and media outlets in France began denying ad block users access to their sites in a coordinated move organised by Geste, a French trade association representing online businesses. The initiative was found to be a success, a result that was supported by a Financial Times study in October – which found restricting access to content to be the most effective way of encouraging users to disable ad blockers.

In August, Facebook began circumventing ad blockers on its desktop site. It took this as an opportunity to take a swipe at the Acceptable Ads program, saying: “Some ad blocking companies accept money in exchange for showing ads that they previously blocked. A practice that is at best confusing to people and that reduces the funding needed to support the journalism and other free services that we on enjoy on the web.” This would see ABP hit straight back questioning Facebook’s decision, before updating its extension to once again block Facebook’s advertising.

AdBlock Plus grows in force
Despite the best efforts of publishers, they were unable to halt ABP’s growth. In May, the ad blocking software hit 100m active users globally. 30 per cent of these users were estimated to be on mobile – reinforcing the fears of mobile advertisers about the growing trend.

In the same month, ABP owner Eyeo teamed up with Flattr, a startup created by Pirate Bay founder Peter Sunde, to create Flattr Plus. The product enables people to fund artists, bloggers and musicians, so people’s favourite creators do not lose out due to an ad blocker.

ABP followed this up a few months later with the creation of its own ad tech supply side platform. In September, it launched the Acceptable Ads platform to enable publishers to programmatically offer advertising. The platform aims to provide publishers and bloggers with a marketplace of whitelisted ads for their sites.

This move, of course, did not sit too well with people within the industry. IAB UKs Phillipson told Mobile Marketing: “Adblock Plus, who spent years as the consumer champion squashing adverts – now sell ads! We see the cynical move from Adblock Plus as a new string in their racket.”

MNOs Shine & browsers block
MNOs and mobile browsers were also getting in on the act of blocking ads in 2016. In February, Three announced it would be introducing network-level ad blocking, after joining forces with Israeli ad blocker firm Shine.

This also, as you might expect, upset those within the industry. And their fears manifested when Three announced its network-level ad blocking trial in May.

However, the prayers of publishers were answered in September when BEREC, the Body of European Regulators for Electronic Communications, confirmed that network-level ad blocking is a violation of the EU’s rules on net neutrality. Despite this, it was not until November that Three decided to completely pull the plug on its network-level ad blocking. However, key reason for the decision seemed to because it had “pissed off” major organisations including Google and Ofcom.

Shine did also join forces, this time successfully, with another mobile carrier. In August, South Africa’s Econet Wireless announced its plans to deploy network-level ad blocking for its customers across Africa.

Operators werent the only ones getting in on the ad blocking game. In May, Opera introduced native ad blocking to its Android web browser. This blocking, however, is not enabled by default but activated through the apps data-saving features.

In January, meanwhile Brendan Eich – the creator of JavaScript and one of the founder of Mozilla – launched Brave, a web browser that blocks all advertising by default. Brave would build on this in the subsequent months with plans to replace publishers’ existing ads with its own. This, as is the theme, made people within the industry very unhappy. The NAA, Newspaper Association of America, calling this practice “blatantly illegal”.

The debate over ad blockers rages on, with questions raised over what advertisers and publishers alike can do about the revenues they lose to them, whether theyre legal and perhaps more importantly whether they should be. 2017 will see more developments from the blockers, resistance from the ad industry and – no doubt – even more fighting between the two sides.