What would you recommend for foreign born US citizens worried about being approached by ICE? What are the basic ground rules for interacting?

For example, some of us here look very much like we didnt grow up in an Iowa cornfield and have genuine concern that one negative interaction is going to result in being roughed up by untrained ICE agents at best and tossed into jail or worse.

Do we just get used to the idea of carrying our passport at all times? Is an ICE agent authorized to demand it and take it from us "for checking", say?

Bar two pieces of fragile paper - a passport and a naturalization certificate - it's not obvious that a citizen is a citizen.