I'm surprised the claims that the stolen passports couldn't be cloned were accepted so readily given the fact that if the ID chip doesn't work the passport reverts to normal paper operation and the user is 'recommended' to get a new one. Getting the chip not to work is quite straightforward.

Besides that - passports are used as ID in a lot of situations where the chip is not read e.g. opening a bank account, so can be used to get 'legitimate' ID which can then in turn be used to replace the passport with a 'legitimate' one.