Bots can be a valuable tool for webmasters seeking additional visibility into their domains. However, malicious variants are a constant headache for online services. Bad BOts are a big problem with respect to DDoS attacks, scraping private data, using fake content or news & also skew advertising & visitor metrics. In 2018, 1 in 5 web requests, i.e. 20.4% of traffic was generated by bad bots alone.