A blacklist response in crypto isn't unheard of either.... They just don't call it blacklisting. An example was when the DAO (ETH token) was attacked and drained of funds, ETH was forked and the user who drained it was unable to use those eth tokens.

If you were speaking of blacklisted tags, this was done to reduce spam. Users can still use these tags if they wish, those specific posts just won't earn UFM or show up on upfund.me....

I don't see this as a limitation on how you can USE your tokens, but a limitation on how new tokens can be EARNED. It's like how you cant mine LTC with a bitcoin ASIC miner, you would require a litecoin mining rig (in other words, a limitation) ...