It works great for intelligence. I have heard they also check sequential #s if one is found to contain drugs, on the assumption that the sender probably sent out multiple packs. This is how intelligence works, it helps narrow in on evidence so that resources are not wasted. Packs crossing customs in particular are checked. If they decide to spend the time window they have checking packs that have tracking checked with Tor, they are probably going to have higher interception rates than if they don't do this. I know of at least three international orders with major amounts of product in them (including blotter paper in two cases) that were snagged by customs after the tracking was checked with Tor, in some cases fairly frequently. If the checking of tracking with Tor was directly related to the interceptions or not is unknown, but I wouldn't be surprised. What legitimate reason is there for a pack from NL to USA to have tracking checked by ten different IP addresses from around the world / Tor exit nodes? This is certainly a red flag regardless of if it is being utilized as one or not, but the ease of utilization makes it seem almost certain that it is being utilized. Checking tracking with Tor by itself may not be enough to get a package checked in the same way that having any other flag present may not be enough to get the package checked. But is it a flag? I would bet on it. I have also heard from multiple people that these tracking checking systems are in place, one person who claimed to have a friend with inside knowledge about Canadian customs in particular was the first person to bring the concern of Tor exit nodes checking tracking to light on a private forum. Highly ancedotal evidence, but the claim makes logical sense if you think about it and I don't see any reason why someone would make up lies about customs doing things that are technically in their ability to do. Even if they are not right now it should always be assumed that they will, since they can.