I don't know what proportion such cases represent compared to others. You said it was a very large number. I'm convinced that it is a considerable number, but I don't really know the true magnitude of it.
We have to remember that contrary to what one may think, witness relocation programs are very difficult for witnesses themselves. A very small number of studies have been conducted with these witnesses, and all of them have corroborated the fact that adaptation is extremely difficult for people who are relocated and who have a new identity. They have a great deal of trouble staying away from their family and friends. Of course, we're not always dealing with people who had excellent social or other skills. So you can't expect miracles either.
There are always many difficulties with adaptation. It's true that we can see this as a situation where people have figured out that they've got a cushy deal or a good way to exploit the system, but on the other hand, we mustn't forget that these are people who have to face enormous and very difficult adaptation.
I hesitate to tell you about certain studies, because they don't have much credibility insofar as they were conducted with a very small number of witnesses. However, they do demonstrate that the risk of suicide, mental illness, depression and so forth is much larger among relocated witnesses than in the normal population.
It's a difficult period and we shouldn't be surprised to see that people will break the agreement they had signed with the police after one, two or three years.