The Jerusalem Post has a story, published today (June 3, 2009) regarding this attempt to shroud checkpoint actions in secrecy:
http://www.jpost.com/servlet/Satellite?cid=1244025958883&pagename=JPost%2FJPArticle%2FShowFull Some quotes:
"The IDF on Wednesday banned Israeli civilians from entering checkpoints around Nablus, in an effort to remove left-wing activists from the sites, where the army says they have interfered with soldiers conducting security checks. "
"This is a protest movement against the occupation and for human rights, to shed light on what is happening far from the public eye,"
"Machsom Watch is opposed to the presence of any Israeli checkpoints within the West Bank, calling for checkpoints to be erected only "on the border between Israel and Palestine." "
"We believe our presence makes violations of human rights at the checkpoints less likely,"