While rate limits and other limits can mitigate these issues, they may also limit the capabilities of honest users. Trustless payment schemes have been explored, but none seem satisfactory, leading to the suggestion that a small bit of trust may not be so bad. The proposal is a system where peers charge each other a hold fee for forwarded HTLCs based on the actual lock time and the htlc value, separate from the routing fee earned when the payment settles. Prepayment or integration with the htlc add/fail/settle messages are ideas for implementation. Hold fees don't need to be symmetric, which prevents channel jamming attacks, and senders will have to be more selective when building a route. The hold fee scheme leverages existing trust relations to present a bill to the actor who deserves it. It is suggested that this spam/jam issue needs to be prioritized and solved before real adversaries show up.