Just as you might vet the domain your email address is hosted with, you want to vet the instance you join. Most instances post information about their admin policies. Some instances post information about their business/hosting model (ie, cooperatives that pay for their instance among themselves, versus people using spare VM cycles "for fun"), and many admins will answer questions about it even if not posted explicitly.
As with email, there's also always the option to use a custom domain you control for your instance. There are a couple of SaaS providers for Mastodon instances like https://masto.host, and cookbooks for several DIY options on major hosting providers. A benefit to custom domain is that you have some power to migrate your CNAME records if you had to switch hosts, and keep your existing followers even.
As with email, there's also always the option to use a custom domain you control for your instance. There are a couple of SaaS providers for Mastodon instances like https://masto.host, and cookbooks for several DIY options on major hosting providers. A benefit to custom domain is that you have some power to migrate your CNAME records if you had to switch hosts, and keep your existing followers even.