There are hundreds, possibly thousands of Palestinians working covertly for the Israeli intelligence services.
They are vital sources of information to Israel but their actions are regarded by most Palestinians as the ultimate in treachery.
For Crossing Continents, Richard Miron gains access to some of the informants who have worked with Israel's internal security agency and finds out what drives them to do it.
If you would like to comment on our programme of any of the issues that it raises please do so using the online form below.
I would like to thank the makers of this programme for a revealing and illuminating insight into this murky and neglected area.
Rina Picciotto, London
Send us your views
The BBC may edit your comments and not all emails will be published. Your comments may be published on any BBC media worldwide.
The comments we publish are not necessarily the views of the BBC but will reflect the balance of views we have received. It is helpful if contributors state if they work for any organisation relevant to an issue discussed. Readers should form their own views on whether messages published represent undeclared interests, or views prompted by a common source.