Over at the Volokh Conspiracy you see a posting on how many times it has been cited in the JLR database.
Using their search parameters I limited the results to those journals with Harvard in the title. There are seven, the most recent of which was from the Harvard Law Review: “Posting of Einer Elhauge to The Volokh Conspiracy, http://volokh.com/archives/archive_2007_05_ 20-2007_05_26.shtml#1179785703 (May 21, 2007, 6:15 PM).” Volokh goes on to discuss the merits of citing to blogs. One commenter also noted that JLR produced results (not citations, just results) limited by year for “britney spears”: 31 results, 2007; 31 results, 2006; 47 results, 2005; 38 results, 2004; 33 results, 2003; 28 results, 2002; 16 results, 2001; 11 results, 2000; 0 results, 1999 (the year …Baby One More Time was released).