Per the story, one of the ways you can get into the ICE database is to have dual citizenship and come into the country on your "other" passport. Frankly, I am the kind of "press to test" person who would do that. I once used my old driver's license with TSA, at National Airport, since the very nice clerk at the Registry told me to hang onto it as an additional form of ID. The TSA person let me through, but I got the additional screening, probably for being a troublemaker.
All that said, this is one more reason why the US Congress needs to take action to make dual citizenship go away. It is scriptural—Matthew 6:24, and common sense. This isn't about football (soccer). What if your dual citizenship is British and Argentinian? Where do you stand when the next war breaks out?
To wrap up, here is an interesting point from the article:
Americans said their vehement protests that they were citizens went unheard by local police and jailers for days, with no communication with federal immigration agents to clarify the situation. Any case where an American is held, even briefly, for immigration investigation is a potential wrongful arrest because immigration agents lack legal authority to detain citizens.Who do you sue? The Feds or your local police?
Regards — Cliff