When Mordechai Vanunu, a humble Israeli technician who worked for years at Israel's secret nuclear site at Dimona, spilled the beans about Israel's nuclear weapons in 1986, very bad things happened to him. He was lured from safety in England for an Italian holiday by a woman who was an Israeli secret agent, drugged and kidnapped from Italy by other Israeli agents, and imprisoned for 18 years (11 of them in solitary confinement).
When Avraham Burg, the former speaker of the Israeli parliament, said last month that that Israel has both nuclear and chemical weapons (you know, like the nuclear weapons that Iran must not have and the chemical weapons that Syria must give up), nothing bad happened to him at all. He is protected by the Important Persons Act, the unwritten law that gets powerful and well-connected people off the hook in every country.
They didn't even go after Burg when he said that Israel's long-standing policy of "non-disclosure" (never confirm or deny that it has nukes) was "outdated and childish." But even 10 years after Vanunu finished serving his long jail sentence, he is not allowed to leave Israel, go near any foreign embassy, airport or border crossing, or speak to any journalist or foreigner.
The Israeli government's excuse for all this is that he may still know secrets he might reveal, but that is nonsense. Vanunu hasn't seen Dimona or talked to anybody in the Israeli nuclear weapons business for 30 years. What drives his tormentors is vindictiveness, and he may well go on being punished for his defiance until he dies - while Avraham Burg lives out his life undisturbed and offers occasional pearls of wisdom to the public.
So here are the "secrets" that Vanunu and Burg revealed, in rather more detail than Burg chose to give and in a more up-to-date form than Vanunu could give from personal knowledge.