Unfortunately I don't know the technicals behind the issue. I assume however, you could implement simple captchas, or use bots to track down accounts that act "unhumanly" and deactivate them. I'd be happy to hear a developers take on this. If bots disappeared, we would be forced to actually meaningfully engage with the community I guess. We could still allow a certain amount of advertisement, as long as it's restrained to a reasonable level