If the FBI can’t follow protocol for actions at the highest levels and engage in amateur tactics, just imagine how they conduct themselves with ordinary citizens. Now, I was under the impression FISA courts has an aversion to allowing spying if there was a possibility of one of the targets being a US national. Witness Martha Stewart. Now, she’s not your average citizen, but you can see how they railroaded her. Yup, t…
It is a crime to lie to federal agents in the course of a criminal investigation. You can avoid committing that crime by not lying to agents. Note that this is not the same as the "if you're honest, you have nothing to hide anyway" argument in favor of mass surveillance. This is about answering a specific set of questions from a member of law enforcement in the course of a specific investigation. You always have the…
18 USC Section 1001 is notoriously broad - for example, your local postman is a federal agent, it doesn't just pertain to law enforcement officials. You don't even need to lie directly to the agent - for example if you fudge your hours on a timesheet and that timesheet gets sent to the federal government for some use or other, you "knowingly and willfully made a materially false, fictitious, or fraudulent statement in any matter within the jurisdiction of the executive, legislative, or judicial branch of the United States."
It doesn't matter if you're not under oath. It doesn't matter if you've been read your miranda rights - any material lie that is made to a federal employee within their jurisdiction is an offense.
Sadly, this means that in almost every case, the only reasonable thing to do is to refuse to talk to the agent and to ask for an attorney if they insist.