Your guess "we do" what? I'm sorry, I'm not certain what part of my post you were referring to.
And to answer your question, do you know that there were other leakers? And, if I read the stories about this correctly, there are individuals who left the Israeli embassy for Israel that the FBI would like to talk to. So perhaps more will be charged, I don't know.
Have 50 Franklin's running around. Unfortunately leaks are endemic in Washington, it would be a good thing to start prosecuting these people. As you noted, the obligation of government employees is clear. Those who are leaked to, much less clear.
And, if I read the stories about this correctly, there are individuals who left the Israeli embassy for Israel that the FBI would like to talk to. So perhaps more will be charged, I don't know.
One individual from the embassy who rotated home. Israel has agreed to allow to have him interviewed, through written questions I believe. The FBI never got around to it while he was here, but the offer is still open as I understand it. Since no one other than Freepers, including the FBI, alleges espionage here, he may not have much to offer. As to other leakers, most articles acknowledge there are others. This article notes two government employees who aren't being charged. It also accuses the ex AIPAC employees of distributing information since 1999. Since Franklin got his job in 2003, clearly others are involved.
BTW, if you recall this story broke during the election, spun as an invective against GWB and his neo-cons. It never got political legs. Until now, virtually all the information has come from FBI and grand jury testimony leaks. We'll get a better idea what happened when the trial rolls around.