On Monday it was revealed that top Trump administration officials were using a commercial messaging app to plan military attacks. What is Signal?

The use of Signal for government business may violate the Presidential Records Act and federal law. Highly sensitive ... editor of The Atlantic, in a group chat on the commercial messaging app ...

The use of Signal for government business may violate the Presidential Records Act and federal law. Highly sensitive ... editor of The Atlantic, in a group chat on the commercial messaging app ...

The use of Signal for government business may violate the Presidential Records Act and federal law. Highly sensitive ... editor of The Atlantic, in a group chat on the commercial messaging app ...