It looks as though twitter may be starting to restrict access to followers information.  In the past this has been an area of the site open to some abuse.  Working on the follow them and they might follow you assumption, some members have been mining the seam of leading members.

Up until recently its been possible to look at a members profile eg. Guy Kawasaki and by simply dividing the number of followers by 20 (the number of followers displayed per page) calculate the total number of follower pages.  In the case of Guy Kawasaki, that’s 84,874 / 20 = 4243.70.

Then these auto follow miners could start on the very first page and work their way backwards clicking follow on every name listed.  Today that seems to have changed.

Only 644 pages are being displayed against his profile Guy Kawasaki (12,888 followers).  This isn’t consistent across all twitters influencers.  A quick check on Robert Scoble shows 718 pages of followers.  So this could be simply a glitch in their back end systems rather than a definite move to block abuse of the service.