Checked the fediverse observer and I see a lot instances with barely any activity skyrocketing to the top of registered users. I can only surmise they're being flooded with spam accounts and haven't noticed.

Example: https://cubing.social/

How much should we worry about this? Should we be taking pre-emptive steps to defederate them to avoid those spam accounts being utilized against the threadiverse?

The spam problem is already on our doostep and we need to seriously start considering how we're going to handle it ASAP. We need to take knowledge from how email dealt with it and find ways to quickly distribute knowledge about spam instances.