Those weren't raids. The difference is minor but no warrant is required and probably none is in hand (limiting other actions the agents can do at during the visit).
The main reason is probably simple politics within the government. FBI is part of "Homeland Security" now and gets its budget from there. When Homeland Security needs money for other things there's always the FBI to cut a little fat from...
The FBI's Taleban Department probably needs badly to justify their budget lest it gets cut and they have to move to other departments where they might be expected to do real work and not sit around the office watching porn all day. Since they don't do any real police work they don't have a lot to show for their salary. Doing these records visits probably lets them fill in departmental checkboxes showing they're doing something, and hopefully senior management won't look too closely and make them go chase drug dealers instead.
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"If they can't picture me with a knife, forcing them to strip in an alley, I don't want any part of it. It's humiliating." - windsock