"Only" in this context doesn't mean "few". If you take it out of the quoted sentence, then the portal could also be available to veterinarians, carnival barkers

"Only" in this context doesn't mean "few". If you take it out of the quoted sentence, then the portal could also be available to veterinarians, carnival barkers, and scuba instructors. But it's not supposed to be available to those people, only to the FBI and other law enforcement agencies.