Namely, Justice Ginsburg, who reportedly fell asleep during the reading of the dueling Heller opinions yesterday at SCOTUS.
And as a commenter correctly points out over at Volokh, this is not the first time Justice Ginsburg has been slumber-challenged in the Courtroom. Back in 2006, during the oral arguments in the Texas redistricting case (League of U. Latin Am. Citizens v. Perry, 548 U.S. 399 (2006), Justice Ginsburg apparently snoozed long enough for the Court artist to capture it for posterity.
In her defense in both instances however, anyone who could stay awake through the redistricting mess was likely chemically-imbalanced, and Justice Ginsburg had no doubt read every word of the 154 pages of opinions in Heller, so there wasn’t any great need for her to remain conscious during the reading of the summaries.

June 27, 2008 at 12:02 pm
“In her defense in both instances however, anyone who could stay awake through the redistricting mess was likely chemically-imbalanced”
Amen to that. Gosh, so many law school memories coming back to me.
June 27, 2008 at 12:39 pm
In all fairness, the redistricting argument was in the afternoon. By the time it reached its second hour (the Court gave it extra time), everyone in the room was ready for a coffee break.