With just over 500,000 followers, the comedian and actor Albert Brooks is a popular presence on Twitter. Most of his tweets are mild, 140-character jokes about events in the news. (Examples: "Neiman Marcus to be Sold for 6 billion. That is, of course, retail," and "Diana Nyad's going to be so pissed when she finds out there was a flight," and "Happy New Year to my Jewish friends, or as I like to call them, my friends.") But Brooks, judging by Twitter at least, has taken the crisis in Syria seriously. Between jokes about Miley Cyrus and Johnny Manziel, on...