BOCA RATON, Fla. -  There's been lots of chatter on social networks in the past several hours about horses and bayonets.

   The exchange between Mitt Romney and President Barack Obama about the size of the Navy has dominated much of the online discussion of last night's debate.

   When Romney said the Navy is too small, and has fewer ships than it did in 1916, Obama responded that there are also fewer horses and bayonets these days -- because the military has been modernized. He said, "It's not a game of Battleship, where we're counting ships."

   On Twitter, the hashtag "horsesandbayonets" immediately began trending in the United States, becoming the top trend in the country and the third worldwide, even an hour after the debate ended.

   On Facebook, users created more than 50 pages named "Horses and Bayonets."