At it's basic level it will capture your IP address, but it won't really tie the IP to a user name, and there's not a role lot you can do with it

Attacks I can think of:

• target advertising at users in a particular lemmy community
• get a collection of IP addresses of people with specific problems or beliefs (indicated by membership in a lemmy community) to target with malware

A VPN would protect you in this case, but you need to be a bit of a privacy nut to also protect yourself from things that identify for advertising right now