I do see a big problem in NSFW section there is a lot of inappropriate stuff, which kids can have easy access these can cause some problems for the developers.
the 2nd problem is the copy and paste of existing articles on other sites.
I am pretty sure that big players like Facebook,Twitter and Co already noticed Steemit and will try to outperform or shut down it Steemit reach 1 Million or 10 Million members. Remeber that they have a very very big fellowship and a lot of "POWER" in the Fiat World but at the moment there is no need for them to make good or bad publicity for Steemit :)