The Media Rating Council, which ensures standards of audience measurement, has removed accreditation for Nielsen’s measurement of its 154 diary-only markets, retroactive to 2009, according to Broadcasting & Cable. The magazine quotes “insiders” who say that with more folks dropping their land lines for cellphones, Nielsen is using address-based recruiting of ratings homes in its diary markets, instead of selecting by phone number. The new method resulted in sample sizes coming up short in two of the four quarters in 2009. Nielsen said in a letter to station clients that the issue has been resolved, it has requested a new MRC audit, and it expects to be accredited again soon. Nielsen’s local people meters took eight years for all markets to secure accreditation.