I don't really get this logic. Take pirate bay as an example. It had more than one domain. They didn't really go after the interface but the source (which didn't fully work anyway). Would they really be that naive to seize steemit.com and let's say busy.org leave untouched? The bigger threat might be a lack of investment killing the platform (due to poor user experience) at the current state. Longer term, who knows - if steemit gets big enough, then it could attract attention.