Perfect mix of high broadband penetration, anonymous, fake or non-existent customer registration, anonymous payment of hosting services, low risk of getting caught – especially when one is known to use violence and / or is armed and dangerous and finally: non-deterrent sanctions.
Financial damage due to cybercrime amounts to 10 Billion EUR in The Netherlands itself.
Dutch language news article:
http://www.telegraaf.nl/digitaal/12487185/__Nederland_springplank_voor_cybercriminaliteit__.html