1. Illegal content

Since there's no censorship possible, it's a guarantee that highly illegal content will surface sooner rather than later. I suspect piracy to be one of the first.

2. Addiction

The dangers of social media are getting more and more known. But if you reward people financially, it's rising to a whole new level!

3. Repetitive strain injury / Carpal tunnel syndrome

People are going to upvote 100's of times a day and will constantly be refreshing their page to see how much they made now, and now, and now, and now. "Just....one.....more".

4. Phishing

Since all "incomes" are public on SteemIt, the most successfull people will almost certainly be victim of phishing- and/or hacking attacks.

5. Botting

If there's money to be made, people will find ways to exploit it. In my opinion it's only a matter of time before SteemIt is filled with 100's, if not 1000's of bots. Some will be positive, but most will be for the sole purpose of exploiting the system to make loads of money.