If you own a laptop you want to keep healthy, you ought NOT to just plug it into any old electrical outlet to charge/run. You'd be surprised at how many buildings have AC outlets that were not wired correctly, which potentially could zap your laptop through a bad charger connection.
For very little money, get this APC surge supressor and rest easy. I have personally witnessed several APC arrestors and UPS units that were badlky damaged by various power line problems. Not one of the computers attached to any of them was ever harmed.