To report another player's base and immediately remove it from your game:
- Interact with the Base Computer
- Choose the option "Report this Base as Offensive or Inappropriate"
- Submit a screenshot of the base as prompted
After the message "Your report has been registered," the problematic base should immediately disappear.
If you are unable to reach the Base Computer to interact with it, a Report Base option is also available at the rightmost end of the the Quick Menu, as long as you are within 50u of any object belonging to another player's base.