You can only do this to sites that skipped or didn’t take seriously enough step 2. Depending on how good the sites filtering requests is, this can range from 100$ linux server running python scripts for account creation. 100 accounts = 100 upvotes. All the way to very sophisticated proxy networking, capcha cracking, in some cases even AI driven internet monopoly demon that isn’t too cheap, so it better be making everyone else miserable enough to make you not think about doing a ninja flip from a 4 story building into a wood chipping machine for a couple of minutes.
What made you come to that conclusion?