From what I understand, it's not so much their skills as an informant/agent provocateur that's appealing, as having them firmly in the pocket of the alphabet agencies. Knowing your handler can single handedly ruin your life (as credible allegations of paedophilia probably would) is one hell of an incentive to stay on their good side and do their bidding, as a matter of self-preservation. Knowing your agent is likely not gonna flip (like a lot of CIA/FBI did in the early Cold War) helps too.