In 2004, fifty-two suspects were arrested in Amsterdam after an extensive raid. An Internet service provider had noticed the increased email traffic. None was jailed or fined, due to lack of evidence. They were released in the week of July 12, 2004. An entirely phony “Nigerian embassy” was also discovered in Amsterdam; another allegedly exists in Bangkok.
In October 2006 the Amsterdam police launched Operation Apollo to fight internet fraud scams operated by West Africans and notably Nigerians. Following this invesigation police have arrested 80 suspects, most of them from Nigeria, and seized from their homes lists of email addresses, as well as fake documents. On June 16, 2007 111 people were arrested for being in The Netherlands illegally and suspicion of fraud, although their implication with the email scams is yet unknown.
Authorities in Nigeria have been slow to take action and for many years nothing was done. Nigeria has a reputation for criminals being able to avoid convictions through bribery and rumours abounded of official connivance in the scams. In 2003 however the Economic and Financial Crimes Commission (EFCC) was charged with tackling the problem. A couple of success stories including convictions in a large 419 case were reported in 2005, but there have been no reports of mass arrests and a large-scale crackdown, and meanwhile the problem continues
Source : wikipedia