>>I do not believe it follows that you can be investigated solely for [any] protected speech, which is what I interpreted your comment to mean.
Then you did miss my point. Often cops/feds have to investigate whether something is or isn't protected speech. When those investigations find nothing (normal) they then appear to have been an investigation into protected speech, but that wasn't clear at the time. We cannot make such investigations illegal simply because they come to nothing.
I didn't say the investigation is/should be illegal if they come to nothing. I said the are/should be illegal if they happen without suspicion that a specific crime has been committed.
The state should not be able to target someone for investigation solely because they disagree with their speech and "think they might be guilty of something." They need to state/establish what that something is. That's my read of Keith.
Material support of designated terrorist organizations is a crime under the law, and investigating someone for that is wholly different from investigating someone solely because they disagree with their protected first amendment activities. Consider again my newspaper example. With terrorism cases, they can point to the laws about supporting terrorism and say that's what the person is suspected of. They likewise need to have a law they can point to that they need to believe is broken before they target the newspaper for investigation because of their speech. How they have to do said pointing (warrants, NSLs, etc.) is a separate question, but in the absence of such suspicion I do believe the search is illegal.
Then you did miss my point. Often cops/feds have to investigate whether something is or isn't protected speech. When those investigations find nothing (normal) they then appear to have been an investigation into protected speech, but that wasn't clear at the time. We cannot make such investigations illegal simply because they come to nothing.