Unidan could just create an account on multiple instances and vote for his posts/comments with all these accounts. That way his content would gain more attention than those of sincere users.
In case of malicious bots (like those annoying bootleg bots on reddit), it might even be profitable for them to create their own instance(s) just for that purpose.
Is there a mechanism to prevent that? (other than user/instance banning and the introduction question on user creation)
Yeah it’s a cat and mouse game sadly…
Couldn’t they keep the instance running and just change the domain name? Or if not easily possible, then just have a setup script that creates a new instance under the new domain name with X number of users.
Sure, but as mentioned it might be easier with Lemmy since they could just run their own instance. Or maybe it’s harder because Lemmy admins check account creation better on their own instance and are more sceptical of other instances.
It’s an interesting topic, time will tell how it’s gonna be. It certainly isn’t bad to talk about it already today. ;)