HackerOne

Founded in 2012 by three Dutchmen who had started out probing big websites uninvited, together with Alex Rice, who had built Facebook's product security team. The platform handles the tedious parts of a bug bounty programme: intake, triage, weeding out duplicates, haggling with the researcher and paying out. The customer gets a contract instead of an email from a stranger with the subject line "urgent".

The breakthrough was "Hack the Pentagon" in 2016, when the US Department of Defense invited outsiders to attack its systems for the first time — with permission and for money. Katie Moussouris served as chief policy officer during the years when rewarding researchers rather than suing them became respectable. Payouts to hackers have since run into the hundreds of millions of dollars.