Depends on the type of info mate.
Say City are trying to whittle down leaks, they release a bunch of different names to different people they have different reasons to suspect. One of the names suddenly appears on a forum. Some hack journalist looking for the next thing to slag city fans comes on here and starts reporting it and the one name finds its way into the mainstream news, if that happens with a single name City know who's leaked it and they're out of the loop from then on or worse, out of a job.
It sounds daft but we're talking high stakes business and City don't like leaks these days so it''s better safe than sorry