I've bought votes for lots of people. Here are the signs... Low effort posts with no engagement, why would someone buy a vote? Doing a lot of it... Low SP, lots of liquid steem. and the money moves from account to account.
It would be hard to mix it up with real effort, engagement and the type of post someone would throw a vote on.
Doesn't stop my paranoia. :P
Yeah, I know it's pretty easy to figure out that these people are doing voting rings. A little harder when they aren't low effort posts. There have been a few high profile people involved in them on here in the past.