If it's coming from Amazon, they don't need to bother with inspecting the package at all. They just need to subpoena Amazon and get the purchase records. The impact of mail scanning only applies to mail whose contents are not already revealed in electronic systems that the feds can more easily access.
I estimate mine is about 50% USPS, 25% UPS, and 25% Amazon's own delivery service. The proportion that's Amazon-delivered has been increasing noticeably over the past year or two.
