A spokesman for the F.B.I. in Washington cautioned against “drawing conclusions from redacted” documents.

“The F.B.I. recognizes the rights of individuals and groups to engage in constitutionally protected activity,” said the spokesman, Paul Bresson. “While the F.B.I. is obligated to thoroughly investigate any serious allegations involving threats of violence, we do not open investigations based solely on First Amendment activity. In fact, the Department of Justice and the F.B.I.’s own internal guidelines on domestic operations strictly forbid that.”

But Mara Verheyden-Hilliard, executive director of the Partnership for Civil Justice Fund, said the documents demonstrated that the F.B.I. had acted improperly by gathering information on Americans involved in lawful activities.

“The collection of information on people’s free-speech actions is being entered into unregulated databases, a vast storehouse of information widely disseminated to a range of law-enforcement and, apparently, private entities,” she said. “This is precisely the threat — people do not know when or how it may be used and in what manner.”

The records show little evidence that the members of the movement planned to commit violence. But they do describe a discussion on the Internet “regarding the Occupy Wall Street movement about when it is okay to shoot a police officer” and a law-enforcement meeting held in Des Moines because “there may potentially be an attempt to stop the Iowa Caucuses by people involved in Occupy Iowa.”

There are no references within the documents to agency personnel covertly infiltrating Occupy branches.

The documents indicate, however, that the F.B.I. obtained information from police departments and other law-enforcement agencies that appear to have been gathered by someone observing the protesters as they planned activities.