It will re-write your hard drive.  Not only that, but it will scramble any disks that are even close to your computer.  It will recalibrate your refrigerator's coolness setting so all your ice cream melts and milk curdles. It will demagnetize the strips on all your credit cards, reprogram your ATM access code, screw up the tracking on your VCR and use subspace
field harmonics to scratch any CDs you try to play.

It will give your ex-boy/girlfriend your new phone number. It will mix antifreeze into your fish tank.  It will drink all your beer and leave its dirty socks on the cof