Recently Mr. Du Bin made and released a documentary "Women above Ghosts' Heads" which revealed the horrible torture happened at the Masanjia Labor Education Camp (aka Laojiaosuo), and edited and published a 600 page book "Tiananmen Massacre".
While according message  from a Chinese human rights lawyer Dr. Teng Biao, a police summon notification was found at the residence of Mr. Du. Another search warranty bearing the seal of Fengtai District Public Security Bureau was also found there. The policemen carried out the search operation were documented as Liu Yang and Li Qiang from Fengtai District Public Security Bureau. There was no name of witness or signature of Mr. Du himself on the paper. Currently no detention notification for criminal investigation was ever seen.
According to this "police summon notification", Mr. Du was charged of suspected violation of "Regulations and punishments in public order and security administration" for "disturbing public order". He was summoned to be questioned at You'anmen Police Station of Fengtai District Public Security Bureau on 14:00, 1 June 2013.
More information about the recent work of Mr. Du Bin can be found in the following references -. These sensitive publications may provide some clue about the possible reason that the PRC government arrested him secretly.
According to Chinese human right activists Mr. Hu Jia and others, a family member of Mr. Du was contacted and two lawyers are ready to represent him. His relatives and friends are very worried about his situation in detention, and are afraid if he had suffered torture, which happened quite often to reporters, human rights activists and even lawyers worked on such sensitive issues in PR China.
 "Women Above Ghost's Heads" Exposes Torture at Masanjia Labor Camp http://ntdtv.org/en/news/china/2013-04-30/-women-above-ghost-s-heads-exposes-torture-at-masanjia-labor-camp.html
 New York Times-Fotograf Du Bin in Peking verschwunden http://www.epochtimes.de/new-york-times-fotograf-du-bin-in-peking-verschwunden-1075873.html
 NTDTV: New Book Reveals Suffering Behind Shanghai Expo; 05-14-2010; http://hrcbulletin.org/hrcb/index.php?option=com_content&view=article&id=92&Itemid=98
The book Shanghai Calvary is a compilation of cruel events that happened leading up to the Shanghai Expo—events that visitors to the Expo may never hear about.
The book is by New York Times photographer Du Bin. He's based in Beijing and published the book in Taiwan.
Bin says his encounters with Shanghai petitioners since last September motivated him to write the book.
[Du Bin, Author of Shanghai Calvary]:
"Because of these events, I felt if I don't do this I will have an uneasy conscience, and that I have wronged myself. Actually, I know there are risks for me to write this, but my conscience felt that I can't pretend I didn't see or hear about these things."
The petitioners in the book are all ordinary Shanghai residents. When preparations for the Shanghai Expo began, many became victims of forced relocations to make way for developing the Expo.
The New York Times photographer says the accounts in his book are just the tip of the iceberg of all the residents victimized around the Shanghai Expo.
Read the entire story and watch the interview : http://english.ntdtv.com/ntdtv_en/news/2010-05-14/848168647966.html
 New Book Reveals Suffering Behind Shanghai Expo ; 2010-05-14; http://ntdtv.org/en/news/2010-05-14/848168647966.html
 Epoch Times - Matthew Robertson: CHINA HUMAN RIGHTS, CHINESE REGIME, MASANJIA TORTURE CAMP, Harrowing Documentary About Slavery and Torture in China Released; May 2, 2013; Last Updated: May 10, 2013 1:33 pm; http://www.theepochtimes.com/n3/36425-harrowing-documentary-about-slavery-and-torture-in-china-released/
 Epoch Times - Aric Chen: Chinese Dissidents Urge Obama to Ask About Filmmaker, Largest ever New York commemoration of the Tiananmen Square massacre gathers; June 5, 2013, Last Updated: June 5, 2013 12:13 pm; http://www.theepochtimes.com/n3/91471-chinese-dissidents-urge-president-obama-ask-about-filmmaker/
 Epoch Times - China: Dokumentarfilm über Masanjia-Arbeitslager hat am 1. Mai Premiere, Aktuelle Nachrichten – China - Menschenrechte, IMPRESSIONEN AUS DER HÖLLE; 29.04.2013; http://www.epochtimes.de/china-dokumentarfilm-ueber-masanjia-arbeitslager-hat-am-1-mai-premiere-1071216.html
 Epoch Times - Jane Lin: 'Women Above Ghost's Head', A documentary about torture at China's Masanjia labor camp; CHINESE REGIME, MASANJIA TORTURE CAMP; April 25, 2013; http://www.theepochtimes.com/n3/23649-women-above-ghosts-head/
 RFA: 《天安门屠杀》一书作者杜斌被证实刑事拘留; 2013-06-09; http://www.rfa.org/mandarin/Xinwen/3-06092013115941.html
 滕彪 @tengbiao 2013-06-09 14:08:48 UTC