Does anyone really think that metal detectors at Major League Baseball will stop attacks?

From My Fox New York:

Entering a big league ballpark will be a bit like going through an airport by 2015.Major League Baseball has told its 30 teams they must implement security screening for fans by then, either with hand-held metal detection or walk-through magnetometers.
"This procedure, which results from MLB's continuing work with the Department of Homeland Security to standardize security practices across the game, will be in addition to bag checks that are now uniform throughout MLB," baseball spokesman Michael Teevan said Tuesday.
The Seattle Mariners announced Tuesday that fans entering Safeco Field will have to walk through metal detectors starting with this year's opener.
Boston, the New York Mets, Oakland, Pittsburgh and San Francisco were among the teams that experimented with screening at times last year. Security gained more intense focus after three people were killed and more than 260 wounded in when two bombs were set off at the Boston Marathon finish line. . . .