The system was designed to allow an upvote on your own post. It even has a check box for it. It was designed and built in. The best way to stop this is to not allow it from the developers side.

Here Are The Steps To Resolve It.

1. Remove the check box.
2. Edit Code To Give An Error & Maybe Even Prompt A Loud Horn Sound For Trying To Upvote Your Own Post.
3. Do Not Allow Upvoting Of Comments The Same Way You Restrict Posts.

Then it would be super manageable to tackle those spam posts with single pixabay photos and the plagiarizers. If people leave the platform fantastic. We will add more people that really want to create great content and over time reclaim the platform and the value of the currency will rise and stay steady.
It really is 3 lines of code.

People can form groups or clubs and work out arrangements for supporting each other. If people think there is excessive activity between just 2 accounts it could be monitored more easily for patterns.

Recently I seen a post where some people were pitching Steem to some investors. There are alot of great things going on with the platform but all of the crap really holds it back. Investors laugh when you leave the room. 40% of their currency is in the hands of scammers? 50% is in the hands of 25 accounts? They said they wanted how much? HAHAHAHAHA