Born 1968. Hacker and one of the founders of internet service provider Xs4all.
While growing up in Wormer in the Dutch Zaanstreek area, he became known as a teenage hacker and appeared as one of the main characters in Jan Jacobs's book "Kraken en Computers" ("Hacking and computers", Veen uitgevers 1985) which describes the early hacker scene in The Netherlands. Moved to Amsterdam in 1988. Founded the hacker magazine Hack-Tic in 1989. Was believed to be a major security threat by authorities in The Netherlands as well as in the USA. In the masthead of Hack-Tic, Gonggrijp described his role as hoofdverdachte ('prime suspect'). He was convinced that the Internet would radically alter society.
In 1993, a number of people surrounding Hack-Tic including Gonggrijp founded XS4ALL. It was the first ISP that offered access to the Internet for private individuals in the Netherlands. Gonggrijp left the company in 1997. After he left XS4ALL, Gonggrijp founded ITSX, a computer security evaluation company, which was bought by Madison Gurkha in 2006. In 2001, Gonggrijp started work on the Cryptophone, a mobile telephone that can encrypt conversations.
Since 1989, Gonggrijp has been the main organizer of hacker events held every four years. Originally organized by the cast of Hack-Tic, these events have continued to live to this day.
Throughout the years, he has repeatedly shown his concerns about the increasing amount of information on individuals that government agencies and companies have access to. Rop held a controversial talk titled We lost the war at the Chaos Communication Congress 2005 in Berlin together with Frank Rieger.
In 2006 he founded the organization "Wij vertrouwen stemcomputers niet" ("We do not trust voting machines") which campaigns against the use of electronic voting systems without a Voter Verified Paper Audit Trail and which showed in October 2006 on Dutch television how an electronic voting machine from manufacturer Nedap could easily be hacked.