The administrators of the DDoS marketplace webstresser.org were arrested on 24 April 2018 as a result of Operation Power Off, a complex investigation led by the Dutch Police and the UK’s National Crime Agency with the support of Europol

https://www.europol.europa.eu/newsroom/news/world%E2%80%99s-biggest-marketplace-selling-internet-paralysing-ddos-attacks-taken-down