Heilbronn and Karlsruhe, both in the southwestern state of Baden-Württemberg, have adopted the tactic to discourage drunken brawling among their younger citizens.

The idea began in Karlsruhe, which has issued around 50 such warnings since November 2008.

“We were desperately searching for an instrument to influence the young people. We bring them to reflect on things,” Björn Weiße, head of the Karlsruhe Public Order Office told the paper, adding that he is now fielding calls from communities around Germany that want emulate the measures.

Heilbronn, just 75 kilometres away, instituted the programme on October 1. Recently five young men there received the first warnings via mail for getting drunk at a wine festival and brutally beating two adults – not long after a man was killed at a Munich S-Bahn stop by two teens.

“Should they not change their behaviour and offend again, this has consequences,” Heilbronn’s Mayor Harry Mergel said. Those caught drinking and fighting are first issued a “yellow card.” A second offence gets them a red card – in the style of sanctioning fouls in football. The offender then loses their driver’s licence or must undergo a psychological examination to determine whether they are fit to drive in order to acquire a licence.

Officials say the key is that offences do not necessarily have any connection to driving.

“The licence is a step towards independence, therefore many are prepared to return to being sensible,” Mengel told the paper. “This is much more effective than detention community service.”