Social media platforms like Twitter and Reddit are increasingly infested with bots and fake accounts, leading to significant manipulation of public discourse. These bots don't just annoy users—they skew visibility through vote manipulation. Fake accounts and automated scripts systematically downvote posts opposing certain viewpoints, distorting the content that surfaces and amplifying specific agendas.
Before coming to Lemmy, I was systematically downvoted by bots on Reddit for completely normal comments that were relatively neutral and not controversial at all. Seemed to be no pattern in it... One time I commented that my favorite game was WoW, down voted -15 for no apparent reason.
For example, a bot on Twitter using an API call to GPT-4o ran out of funding and started posting their prompts and system information publicly.
https://www.dailydot.com/debug/chatgpt-bot-x-russian-campaign-meme/
Bots like these are probably in the tens or hundreds of thousands. They did a huge ban wave of bots on Reddit, and some major top level subreddits were quiet for days because of it. Unbelievable...
How do we even fix this issue or prevent it from affecting Lemmy??
Long before cryptocurrencies existed, proof-of-work was already being used to hinder bots. For every post, vote, etc., a cryptographic task has to be solved by the device used for it. Imperceptibly fast for the normal user, but for a bot trying to perform hundreds or thousands of actions in a row, a really annoying speed bump.
See e.g. https://wikipedia.org/wiki/Hashcash
This combined with more classic blockades such as CAPTCHAs (especially image recognition, which is still expensive in mass despite the advances in AI) should at least represent a first major obstacle.
Why resort to an expensive decentralized mechanism when we already have a client-server model? We can just implement rate-limiting on the server.
Can't this simply be circumvented by the attackers operating several Lemmy servers of their own? That way they can pump as many messages into the network as they want. But with PoW the network would only accept the messages work was done for.
Rate-limiting could also be applied at the federation level, but I'm less sure of what the implementation would look like. Requiring filters on a per-account basis might be resource intensive.