The justices themselves exercise plenty of care, whatever the reason. Kagan, speaking in Providence, R.I., last August, said that when the justices communicate with each other in writing, they write memos printed out on paper that looks like it came from the 19th century. Aides carry the documents from one justice's chambers to another's.
Television cameras remain barred from the courtroom, and some justices limit the use of tape recorders when they make public remarks.
Of course, the Supreme Court is asked frequently to set national rules on complicated topics about which the justices have imperfect knowledge.
It was Scalia who noted his inability to join some parts of Justice Clarence Thomas' majority opinion in a patent case in June dealing with molecular biology. "I am unable to affirm those details on my own knowledge or even my own belief," Scalia said in a brief separate opinion.
Follow Mark Sherman on Twitter @shermancourt.