Google AI says

[speak easy]

Immigration officers can do a basic on-the-spot search of devices, the ACLU says. They can download the full contents of your device, including data – meaning they effectively get access to everything. Officials can keep the device for longer – from days to months – if there are “extenuating circumstances".

No Gemini, Ma'am, Citizens do not have to hand over their Phones. If you are on a visa you are on your own.

[WhiskeyGrinder]

1. .

Citizens do not have to hand over their phones.

That's not true. CBP claims authority over everyone at point of entry.

[speak easy]

2. 'CBP claims authority'

Do they exercise it? The CBP has no authority to deny Citizens entry into the United States that I aware of.

[WhiskeyGrinder]

3. .

Do they exercise it?

Yes, they do. Most recently/publicly on Amir Makled:

https://www.npr.org/2025/04/09/nx-s1-5357455/attorney-detained-by-immigration-authorities

Earlier this week, Michigan-based attorney Amir Makled was detained by federal immigration agents while returning home from a family vacation to the Dominican Republic.

On Sunday at the Detroit Metro Airport, Makled — who is a U.S. citizen — attempted to pass through customs with his wife and children. The rest of his family was able to enter the country without issue. But when Makled's turn came, he overheard one of the agents call for assistance from the "Tactical Terrorism Response Team."

(snip)

Border agents pressured Makled to hand over his cell phone. He refused. After more than 90 minutes of back-and-forth, he eventually showed agents his contacts list. He was eventually released. Makled says he was never given a reason for his detainment.

The CBP has no authority to deny Citizens entery into the United States that I aware of.

This is correct. But delay and detention are tools they can use in the meantime.