Israeli rights advocates say that such comments by officials have fostered an atmosphere of harassment. While they do not accuse the government of orchestrating a campaign against them, they point to a number of seemingly unconnected dots that they say add up to a growing climate of repression.

In Sheikh Jarrah, the East Jerusalem neighborhood where several Palestinian families have been evicted from their homes and replaced by Jewish settlers, the police have arrested dozens of Israelis attending peaceful protests in recent months. Mr. El-Ad was detained for 36 hours in January, along with 16 other activists, after he explained to the police that their decision to break up a rally had no legal grounds. One organizer of the protests was arrested at his parents’ Jerusalem home on a night in late March, and released three days later.

Sari Bashi, the director of Gisha, an advocacy group that focuses on freedom of movement for Palestinians, said her organization was harassed last year by the Israeli tax authorities. She said they questioned why Gisha should be tax exempt when that status was meant for organizations that promoted the public good. Eventually, she said, the authorities backed down.

Then an ultra-Zionist nongovernmental organization called Im Tirtzu (Hebrew for ‘If you will it’ — the first part of Theodor Herzl’s famous maxim) attacked a major organization, the New Israel Fund, which channeled about $29 million to Israeli groups in 2009, including some Arab-run, non-Zionist groups. The fund describes itself as pro-Israel and says it does not agree with all the positions of the groups it helps, but it supports their right to be heard.

Im Tirtzu published a report in January asserting that 92 percent of the quotes from unofficial Israeli bodies supporting claims against Israel in the Goldstone report were provided by 16 nongovernmental organizations financed by the New Israel Fund.

The New Israel Fund dismissed Im Tirtzu’s findings as a fabrication, saying most of the references it cited had nothing to do with Gaza during the Israeli offensive.

Still, for three weeks, Im Tirtzu plastered billboards across the country with posters featuring a crude caricature of the New Israel Fund president, Naomi Chazan. The posters depicted her with a horn attached to her forehead (in Hebrew, the word for fund also means horn) and bore the legend “Naomi Goldstone Hazan.”