I was once followed by the FBI (without my knowledge). They were following someone I knew and I was at their house frequently. They did this for quite some time

I was once followed by the FBI (without my knowledge). They were following someone I knew and I was at their house frequently. They did this for quite some time. I ended up having to meet with an agent to answer his questions. I made sure to meet him at lunch time so he could buy me lunch if he needed me. It ended up being at a coffee shop. He explained to me a situation and wrapped the case (it was a false alert). He promised I would never hear from him again or his agency, but with these guys who knows. I felt a bit weird, but one thing is for sure, if the FBI is following you at least you have somewhat of a protection.