EDIT4: For those reading this after the dust has settled, I've changed my position. This is not a perfect solution as it would solve manipulation via VPNs, but not manipulation via botnets. There has to be a more elegant solution, I just don't know what it is. Please don't forget that this issue exists though, it could be the death of Voat.
By combining a VPN with multiple accounts a user can easily manipulate this site. Submit posts with main account and upvote with alt accounts (using a different IP for each one) to reach the front page. For extra power, create posts with alt accounts and upvote with other accounts to gain the ability to downvote. Combine with scripts to control the front page.
Edit: just think about it, how many accounts would it take to control the front page? Around 100 FYI.
Edit2: seriously, if anybody has a better solution please speak up.
Edit3: apparently I wasn't clear; I'm talking about just blocking voting, not posting or commenting.