Parcel carriers are penalizing customers who attempt to use consultants to negotiate lower rates.

This is flagrantly anti-competitive.

I don’t think the government should be involved, however. Parcel freight customers are choosing to allow carriers to overcharge them. They are aware of what is happening (so it is not fraud) and they can always accept the higher cost of working with another organization–forming their own logistics network, or using USPS.

But the freight carriers are pretending this is not collusion, it’s just coincidence:
“At an industry conference in late 2009, UPS and FedEx executives went public with their intent to minimize their dealings with consultants. In separate internal policy memos the following spring, they codified that intent, essentially forcing shippers to negotiate directly with them or risk having their contracts canceled and all the pricing benefits associated with the contract eliminated.”