After being ordered to block a number of piracy-related domains following a complaint from academic publisher Elsevier, Swedish ISP Bahnhof retaliated by semi-blocking Elsevier's own website and barring the court from visiting Bahnhof.se. Those actions have now prompted Sweden's telecoms watchdog to initiate an inquiry to determine whether the ISP breached net neutrality rules.

It’s safe to say that Swedish ISP Bahnhof is one of the most aggressive companies when it comes to defending its customers from interference initiated by outside parties.

The ISP is an outspoken critic of copyright trolls and has taken a number of measures to ensure that it’s extremely difficult for them to identify Bahnhof subscribers. It also believes in the open Internet and by extension is against site-blocking efforts on copyright grounds.

In November, however, it became clear that Bahnhof would be joining the ranks of other blocking ISPs after a court ordered it to block a series of domain names following a complaint from academic publisher Elsevier.

At the time, CEO Jon Karlung told TorrentFreak that the “horrifying” decision, which targets Sci-Hub domains including sci-hub.tw, sci-hub.mu, sci-hub.se, libgen.io, “goes against the soul of the Internet.”

A clearly incensed Karlung then did something that has never been done before. In a retaliatory move, he prevented his subscribers from accessing the official Elsevier.com website directly, sending them instead to a landing page containing an advisory notice about blocking and an option to click through. This was done to give the publisher a taste of its own medicine.

The maverick businessman didn’t stop there though. On top, he ordered his team to ensure that users of the court’s network could no longer access Bahnhof’s website. These protests were designed to provoke a debate about net neutrality and that, it now transpires, is something that will come to pass.

An announcement by the Swedish Post and Telecom Authority (PTS), which acts as the national watchdog for the electronic communications and postal sectors, reveals that it has launched an investigation into Bahnhof’s actions.

“The Post and Telecom Agency (PTS) is investigating whether the internet service provider Bahnhof has taken measures to influence access to websites,” PTS says.

“A key rule in EU regulations in this area is that all traffic on the Internet should be treated equally by providers of internet connection services. PTS’s task is to monitor and ensure that the provisions on an open internet, also called network neutrality, are complied with.”

Noting that Bahnof has implemented measures that have restricted access to websites, PTS says it is now investigating whether Bahnhof breached net neutrality rules.

After being adopted on November 25, 2015 and coming into force on April 30, 2016, Regulation (EU) 2015/2120 enshrined net neutrality provisions into EU law, including non-discriminatory traffic management.

PTS says it will seek to detemine if Bahnhof’s actions are in line with the Telecoms Single Market Regulation, noting that ISPs may not block, alter, or discriminate against specific content.

ISPs in the EU are, however, able to implement traffic management measures beyond those that are normally considered “reasonable” in order to comply with legal requirements, such as blocking sites in response to a court order.

Speaking with TorrentFreak, Karlung says the situation can be interpreted as “the essence” of irony.

“Bahnhof gets a legal threat to block sites out there somewhere on this huge computer network called the Internet. We block the sites because in reality there is no legal chance to win cases against the copyright mob, since the judge and court are corrupt, and it also comes with a package of astronomic fines,” he explains.

Karlung says that the PTS appears most interested in the ‘counter-blocking’ of Elsevier, which he characterizes as a “fine opportunity” to tell people about the dangers of site-blocking which targets “the soul and core” of the Internet.

“[Blocking] also jeopardizes the principle for ISP’s to be able to operate services. The ISP can never be responsible for content, or what people are doing somewhere out there on the Internet.”

Bahnhof’s CEO says he hasn’t yet seen any formal questions or demands from PTS about his company’s “counter-blocking” but it’s clear he’ll relish the chance to bring this issue to the attention of a wider audience.

“We will of course not let this go unnoticed, and I heartfully thank PTS for this fine opportunity,” Karlung concludes.

PTS says it will be sending questions to Bahnhof which will require a response by January 17, 2019.