https://github.com/brendan-rius/darkmall
Educational purposes only. Do not do anything stupid.
It is possible (and should have been done already) to create a decentralized market on the Ethereum blockchain that cannot be taken down, and with a way better user experience then previous markets (no signup/login required, no TOR required).
This link is a very partial draft implementation for educational purposes. I will not maintain this project but contributions are welcome.
This is the next logical step with all the uncertainty and takedowns going on. One thing I will add though, is with open-source markets like this, the code really has to be thoroughly audited before being pushed to the chain, or catastrophic things could happen.