Have you thought why third world countries need in their country have found refuge thousands of criminals? No amount of money will justify itself. Besides, all criminals tend to organize gangs, and this is a threat to the state.
No. I don't think that these criminals pose a threat to the third world nations. They will remain in the prison during their jail term. Once their sentence is over, the criminals will be deported back to their own countries. The third world nations which house them will gain, in the form of increased employment and financial grants.