Price-comparison service Idealo sued Google in a Berlin court, claiming that the tech behemoth has made it harder for users to find Idealo on the search engine since it began promoting its own price-comparison product Google Shopping. Ideola’s suit also names Google Ireland, Alphabet’s European body, and seeks €500 million in damages. The suit is based on the European Union’s two-year old ruling that fined Google €2.42 billion ($2.72 billion) for favoring its own offerings over those of competitors.

The Wall Street Journal reports that, at the time of that earlier ruling, EU competition commissioner Margrethe Vestager “encouraged companies to use the ruling as a basis to seek damages against Google.”

WSJ adds that, should Idealo’s suit succeed, it would likely encourage other Europe-based technology firms to take on Google. Idealo, which is majority owned by publisher Axel Springer, “also claims Google violated the 2017 decision by failing to alter how it promotes its own services in search results even after being fined.”

Google hasn’t commented since it hasn’t seen court filings yet but, in March, Google senior vice president of global affairs Kent Walker stated that the company has “already made a wide range of changes to our products to address the commission’s concerns.”

Idealo’s attorney, Thomas Höppner, “said the potential damages could increase substantially should the judge accept his demand to subpoena data from Google to determine the exact scale and period of the alleged antitrust violation.” Although Vestager has stated that, “competition in the sector was improving and that Google was compliant,” Höppner said that, “the proceedings could bring about new evidence.”

Idealo chief executive Philipp Peitsch stated that, “we want to set an example with this lawsuit that one can defend oneself against the illegal behavior of Google.” BEUC, a European federation of consumer protection groups, also “wrote to the commission last Friday alleging that Google wasn’t in full compliance.” According to Idealo, its visibility, which was measured by Sistrix, an independent online monitoring service, “dropped by half in the two years after Google started promoting its own price-comparison service on top of search results” and currently is still “far below its peak of late 2013.”

A U.K.-based price-comparison company, Kelkoo Group, had taken action against Google before the EU commission’s decision, and Kelkoo chief executive Richard Stables added that “Google’s changes since the 2017 ruling weren’t making a significant difference for companies like his,” and that it will “now use evidence cited by the Commission in its own litigation” against Google. “These huge fines are just a tax for Google to take over the Internet, but there is no change in behavior,” said Stables.

Referring to Idealo’s lawsuit, European Commission spokesperson Ricardo Cardoso stated that, “the Commission takes note of the ongoing national proceedings concerning potential damages related to Google’s anti-competitive behavior in the comparison shopping service market.” He added that, “a Commission decision constitutes proof that the behavior took place and was illegal, giving any individual or company affected by Google’s antitrust breach an opportunity to take to the courts.”