New Delhi, Aug. 8 -- RAMALLAH - Sam Sherman was in Masafer Yatta when the email arrived.

The message informed him that Israel had revoked his electronic travel authorization. No charge had been filed against him. No reason was provided. No formal process had been conducted. He had simply been added to whatever list Israel maintains for American Jews who stand with Palestinians in the occupied West Bank, and the list had reached his name.

Sherman was doing what the network of activists he worked with calls protective presence - traveling to Palestinian communities in the South Hebron Hills to document settler attacks and insert an American witness into encounters that, the theory goes, might turn violent if no one from outside the territ...