After I played a little bit with Qora API, I consider to create a small app which stores arbitrary data on the blockchain by encode the data to byte64. What I ask myself, how do you want to prevent illegal files (for example images) stored in the block chain? Or a further example that came to my mind, a terror organization starts to use the blog system to announce information there?
I have thought that about a while. We could have a separate black list curated by people which if downloaded to your wallet would get rid of and block all those objectionable things. There could be a separate website out there with blacklists curated by different groups (who crowdsource it to their members), so you can just download the most reputable one from time to time and update your software. That way you would avoid all the bad stuff. Also, I think there should be a way so that those groups that curate lists get paid in some way that is built in into the software.
I think crowetic (et al) have it in the road map to use whitelisting for qora as it exists now. Qora 2.0 will use encryption on the blockchain. I don't think the final decision has been made, but whitelisting is easier than blacklisting.