Hackers caused a massive traffic jam in Moscow by exploiting the ride-sharing app Yandex Taxi and using it to summon dozens of taxis to a single location. While Yandex has not confirmed the attacker’s identity, the hacktivist group Anonymous claimed responsibility on Twitter. The group has been actively taking aim at Russian targets in response to the Russian Federation’s ongoing invasion of Ukraine.

Yandex claims that it has implemented new algorithms to detect this type of attack in the future and will compensate the affected drivers.

This traffic jam is a new application of an old hacktivist tactic: flood the system to make it unusable. Other techniques in this vein include blackouts (which target fax machines) and distributed denial of service (which targets websites and networks). No word yet on whether this new rideshare jam exploit will merit a snappy title.