They just don't care about people importing five grams of pure crystal LSD? Of course it is intuitive to think that if they have the address and want the person they will get them from doing manned surveillance, but in practice I have seen that this is not always how things work out for them. The tracking says something about it being intercepted or other suspicious things, everyone in the group order is raided and the people with fake ID boxes just don't go to pick up. Also there are of course other benefits, it is no longer a game of recording addresses on the outgoing mail of a single person who is under surveillance, but becomes a game of putting all of these widely distributed points under manned surveillance waiting for people to pick up packages, the difference in cost between these two sorts of operation is enormous when you consider a vendor serving a customer base of a hundred people. It is the difference between a single agency actively pursuing that vendor and dozens of agencies cooperating to actively pursue the entire network. It also has the added benefit of being able to ditch the box after the vendor you work with is busted or starts acting suspiciously, not having a history of a hundred random packages from all over coming to your home address. Not to mention you are no longer worried about being blackmailed with your address if you work with the wrong person. What if you decide to start vending later and one of the vendors you worked with turns out to be a fed, it is the difference between them knowing who you are and them knowing a box that you used once that they never bothered to put under surveillance. I personally think that people writing off fake ID boxes have unrealistic expectations about the plausible deniability that they have, if you accept a package of drugs and open it and are raided half an hour later you are going to be charged for possession of those drugs and no story you make up about how you had no idea drugs were coming to you is going to do shit to protect you.