However, in a case involving umbrellas, a German regional court has now confirmed that this practice (in particular when it involves emails) constitutes “unacceptable harassment” under the country’s competition laws. Or, as it is marvellously phrased in the law itself, “unconscionable pestering.”

The court, in the North Rhine-Westphalia city of Hamm, on Monday backed up a ruling last year by a district court in Arnsberg. Again, this is technically a dispute between parasol merchants, one of which is an Amazon merchant, and Amazon itself is not the defendant. However, the ruling does effectively say that Amazon’s function is illegal.

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Why? Because the person on the receiving end of the recommendation email has not consented to receive such marketing material.

There is precedent for this legal fightback against unsolicited advertising, and signs that it could intensify.

Just this month, Germany’s supreme court ruled that Facebook’s Friend Finder function, which encourages users to get their friends to sign up, also constitutes harassment and unfair trading practices.

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That case was lodged by the Federation of German Consumer Associations. The German senate last month passed a new law that will allow consumer associations to launch data protection suits on their own initiative, without even needing to wait for complaints from alleged victims—and putting people on marketing lists without their consent can also be framed as a data protection offense.

In other words, we may soon see German crackdowns on this sort of activity coming from multiple legal angles.

Amazon has not yet said whether it will now stop using the “share” function in Germany, but either way, the judgement is a sign of the times.