This is very much NOT trustless, as should be apparent from this quote from the specs: If the value of ETH drops precipitously relative to BTC, then the dollar

This is very much NOT trustless, as should be apparent from this quote from the specs: If the value of ETH drops precipitously relative to BTC, then the dollar value of the ETH bonded by the signers can be less than the dollar value of the BTC deposit they have backed, meaning they have positive expected value if they try to steal the BTC. In order to avoid that, we require that the bonds are overcollateralized. For each ETH they collateralize, they must put up an additional 50%, for a total of 150% collateralization rate.