While some are outraged about the Transportation Security Administration's choice to allow small knives on planes, others support it. When writer Joe Sharkey collected comments about the move, he noted several female business travelers said they carry pen knives, which will be allowed when the new rule goes into effect in April. "People who don't understand why anyone would want a small knife on a plane are missing the point. Many people like to carry around a pen knife in their pocket or purse for the small tasks of everyday living for which such a knife is so useful. And these people don't want to have to remember to take the knife out of their pocket or purse every time they fly," one female reader said.