The law here is not completely developed. The US Supreme Court has not ruled on the extent to which electronic devices of a US person may be searched at a border.
In practice, courts have generally allowed manual, cursory searches of electronic devices (such as looking at recent photos) as being similar to a search of luggage. However, courts have disagreed on how intrusive the search can be and whether a more invasive search at the border can be conducted without some additional suspicion.
In practice, courts have generally allowed manual, cursory searches of electronic devices (such as looking at recent photos) as being similar to a search of luggage. However, courts have disagreed on how intrusive the search can be and whether a more invasive search at the border can be conducted without some additional suspicion.