I don't remember who I was talking with about the Polish hooligans in Germany but check this out
http://news.yahoo.com/s/ap/20060614/ap_on_sp_so_ne/soc_wcup_security
'Four known hooligans were arrested near the soccer stadium and found to have knives after Polish police in town for the game pointed them out to German authorities, Dortmund police spokesman Georg Blaszyk said.'