The Wednesday fine stemmed from a suit lodged by a national taxi union back at the end of 2014, over Uber’s alleged contravention of a law from that year that banned several Uber-like practices.

One of those rules states that drivers from such services cannot wait on a public road between fares, but must instead return to a parking area until their next pre-booked appointment begins. The idea is to stop them from behaving like, well, taxis.

The taxi union complained that Uber’s driver-training videos were less than explicit about this point, and the Paris commercial court agreed that the videos encouraged drivers to go to areas with high demand, and to accept fares from people even when they did not fall into the legally mandated scenario.

The court told Uber to cut it out, but the union noticed that some of the training videos stayed up on YouTube during the first quarter of 2015. Hence the fine, which goes to the union, and which Uber is appealing along with the original ruling.

Uber’s take on this is that the underlying law itself is null and void, as it does not comply with European legislation. The firm points out that the French government failed to notify the European Commission about the so-called Thévenoud law, which also bans private-hire drivers from using software to find clients, before passing it.

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This matters because Uber claims to be an “information-society service” rather than a taxi firm, and EU countries are supposed to tell the Commission about any new laws targeting information-society services before putting them into practice.

“The merits of the case on which today’s decision was based are already under appeal. Clearly we will appeal this particular outcome too. There is a question mark over the very law itself, which the European Commission is investigating,” Uber said.

Uber’s service was one of the subjects of protests this week in Paris, with taxi drivers blocking traffic and burning tires in outrage over the practices of the firm and others like it. They say the authorities have not properly enforced the Thévenoud law and their revenues have recently fallen by 20-40% — which is particularly tough when they have to pay around €200,000 for a license to operate a taxi and their new-fangled rivals do not.

France’s constitutional court has already ruled that drivers can work for both traditional cab companies and services such as Uber, and Uber said last week that it wants to open up its platform to taxi drivers. A taxi syndicate representative told The Verge this was a “provocation.”