A German regional court has ruled that adjusting web pages to block advertising is legal activity, following several complaints raised by German publishers against Eyeo-owned Adblock Plus.

The four-month trial has heard arguments for and against the use of ad blocking services. Those in favour believe that ad blockers are necessary to ease the navigation and usability of a site, whereas those against its use argue that advertising is essential to maintain the financial vaibility of a website. In addition, critics suggest that ad blocking gives way to a vicious circle whereby an increased use of the service forces advertisers to post more intrusive ads in a bid to fight for higher conversion rates with a reduced audience.

Zeit Online and Handelsbatt, two German-based publishers, took Adblock Plus to court as it sought to make its popular ad-blocking packages illegal in the country. They argued that its parent company Eyeo did not have the right to modify websites that it did not own.

Eyeo fought back noting that it was not altering anything that the computer’s owner did not directly request to be modified – an argument which the Hamburg court considered valid.

The final decision confirmed that ad-blocking is legal in Germany: “We are extremely happy with the decision reached today by the Hamburg regional court,” an Eyeo official said in yesterday’s statement.

“This is a victory for every single internet user because it confirms each individual’s right to block annoying ads, protect their privacy and, by extension, determine his or her own internet experience. It is living proof of the unalienable right of every user to enjoy online self-determination,” the spokesperson continued.

In a blog post Adblock Plus’ Ben Williams added: “The Hamburg court decision is an important one because it sets a precedent that may help us avoid additional lawsuits and expenses defending what we feel is an obvious consumer right: giving people the ability to control their own screens…”

It is though that this case and result will influence similar legal considerations across Europe.