外国人不法労働者を通報するサイト

法務省入国管理局のサイトの外国人不法労働者を通報するフォームは，不法労働者について細かな情報を求める他，通報者については，年齢と住んでいる県名だけ記入すればいい。

It also asks informants to report detailed information on a suspect's job and residence, including their company's name, location and phone number. The hours of operation of the company can also be included, along with the times the suspect is most often at home.
And while the form does ask the informant to include their name, address, phone number and e-mail address, these boxes can be left blank, except for the sections on their ages and the prefectures in which they live.

http://www.japantimes.co.jp/cgi-bin/getarticle.pl5?nn20040220a4.htm
http://www.immi-moj.go.jp/cgi-bin/datainput.cgi