Everybody talks about bots but let's not forget that there are plenty of bot-like accounts controlled by humans from poor countries for (fractions of) pennies.

Everybody talks about bots but let's not forget that there are plenty of bot-like accounts controlled by humans from poor countries for (fractions of) pennies. You don't need a "hacker army", just a couple of bucks and a third-world nation with good enough infrastructure. Look up "click farms". The problem with this is that while bots can be detected (even if doing so is an arms race) it's much harder to detect "bot" humans.