I have worked in the shipping industry for a long time and it is highly unlikely that a mail carrier, UPS or Fed Ex driver will knowingly be part of a controlled delivery for a number of reasons. A delivery person does not have to be a part of a law enforcement operation, that is not their job. I know of one instance where a driver delivered a package and the house he delivered to was later raided because the package was full of meth. The cops and loss prevention had let the pack be loaded and delivered, but the loader and driver had no clue what was going on and the driver was very pissed and the union tore the company a new ass for putting him in that situation. People who deliver the same route day after day do not want to be looking over their shoulders for people who think they are to blame when they get busted, playing cop is not part of their job. Plus, most delivery drivers really don't care what people are shipping as long as it is not hazardous. A controlled delivery will usually consist of a cop who is dressed the part and given a company vehicle to drive by someone in loss prevention who is working with them. If a regular driver is involved then it would be because they wanted to be and their supervisors allowed them to. Of the people I work with, I can't imagine one of them who would do that and anyone who was forced to would be in a great position to sue the company.