Lying to a federal agent is a felony, and often times they don't have enough evidence for the original crime, but by talking to you they get evidence of you lying
It's worse than that -- often their MO is to deliberately get people rattled so they say something false (that the FBI already knew was false), then charge them for that. It's stupid, but it's currently the [courts' interpretation of] the law. (The written law has a materiality requirement, but this has been interpreted so loosely as to be irrelevant.)
With this law on the books they often operate under the same practice/advice you hear given to attorneys in court: "only ask questions you already know the answer to".
In many/most cases if they're asking questions they already know the truth behind at least some of them. They are attempting to leverage you into cooperating against co-conspirators or at least be able to hit you with a felony for misleading/false statements in the event the original investigation doesn't pan out to charges.
If you can, get past his ideology and that he was a Trump guy, the actual process of what happened to him and what he was charged with is pretty crazy.
He was very stupid for talking to agents without a lawyer. But, they went in and got him to lie about something that wasn’t a crime, and he didn’t actually do.
As a member of President Trump's transition team, Flynn made a pair of direct diplomatic requests to Russia's ambassador to the United States (Russia complied with both requests). Later, during an FBI counterintelligence investigation centering on Russia, Flynn lied twice about having had those diplomatic conversations at all. The case was later dropped because the entire overarching investigation (Crossfire Hurricane) --- which did not center on Flynn --- was dropped.
Flynn is a cut-and-dried example of how 18 USC 1001 can make sense. He wasn't entrapped. He hung himself out to dry. It's a great example of the logic of this thread and the post: don't talk to federal agents, because if you're an idiot and try to bullshit your way past basic facts of their investigation, they'll convict you for it.
I think this case is the prime example why lying to a federal agent ought to not be a crime at all. Why should I go to prison and have a felony if Michael Flynn doesn’t have to? If I have to go to prison, so does Michael Flynn.
Lying to a federal agent is a felony, and often times they don't have enough evidence for the original crime, but by talking to you they get evidence of you lying