Have their been other do-it-yourselfer alarm systems on the market before?
Yes, but first the were not plug and play like Laser Shield. They required some installation and programming. And they are far more complicated. Some require attachment of magnets to windows and doors, and you still have to string wire between detection units in some cases. Many do not come with monitoring, only a pager-alert to the owner and a siren. None have had much success and some already have been taken off the market.
