I don't see harm if someone really wants to sign this, but keep in mind that president does not give a damn about what gun owners think, and is not interested in including gun owners in the "national conversation" about this crime, regardless of the verbal bones he throws to his lapdog media. What will be more effective is to send something similar to make your views known to your congressional representative and, if you live in a red or purple state, to both of your senators-- especially if they are up for re-election in 2014.