In a high-tech hunt for hooligans, Dutch police sent 17,000 text messages Wednesday to mobile phones of fans who attended a soccer match between rival clubs Ajax and Feyenoord in Rotterdam last season.
Supporters rioted before, during and after the April 17 match, which Ajax won 3-2. Two train cars were vandalized beyond repair, 43 supporters were arrested, and 47 police officers and an unknown number of fans were injured.
Phone companies voluntarily handed over the mobile phone numbers of people who were in or around Feyenoord's Kuip stadium on the day of the match traceable using broadcasting masts in the area.
The phone companies did not give individual names to police, and police sent a standard message asking people to come forward if they had information.
But some suspects apparently thought they had been fingered. Four suspects contacted police Wednesday, and a fifth turned himself in directly, Rotterdam police spokesman Ger de Jong said.
"Maybe they just think, 'I'm going to get caught sooner or later so I better just turn myself in and get it over with,"' De Jong said.
Rotterdam police also filmed the clashes, and have posted images of suspects on their Web site, drawing complaints from privacy groups.
De Jong said the text messages and Internet site were simply examples of officers applying traditional investigation techniques to new media.
"This is no different than the requests for information we publish in newspapers or on television," De Jong said, reports the AP.