And yet a great, great many convicted felons do not report criminal contacts. I point to the number of convicted felons who go on to commit another felony in company of other criminals. Furthermore, I am led to believe that a culture of physical violence towards informants means that a felon who reports on other criminals is, frankly, asking for trouble. I wouldn't be surprised if the majority of felons do not habitually inform on each other.
They like to make an example of computer criminals. Locking up a marginal rapist, murderer, gang member, etc. doesn't serve any useful political purpose -- it just makes crime stats look worse.
As a felon, I would err on the side of reporting criminal contacts.
(I personally also have an obligation to report compromises of classified data, too, so I would have reported this.)