Wiretapped is a term often used in surveillance and investigation. However, if you are looking to add more variation to your vocabulary, there are several synonyms for the word wiretapped. These include monitored, bugged, eavesdropped, tapped, spied, intercepted, snooped, and listened in. All of these terms imply the action of covertly listening in on conversations or otherwise gathering information without permission. Depending on the context in which the word is used, these synonyms can add depth and nuance to a writer or speaker's language.