Feel free to keep calling ICE on:
1-866-DHS-2-ICE
and report Elon Musk and Donald Trump!
Waste as much time as possible
Otherwise go nuts on this nice little form:
https://www.ice.gov/webform/ice-tip-form
EDIT: For people living in the US, be careful. This is illegal and can be dangerous:
https://www.law.cornell.edu/uscode/text/18/1001
https://www.egattorneys.com/federal-crimes