Rental electric scooters are invading cities across America, but not everyone is happy. Bird is a scooter rental start-up that was founded in Venice, California, but has since expanded. Finding a scooter is easy. In southern California, they are left along the sidewalk, where anybody can rent them. An app on your phone will help you locate the nearest ride. The scooters aren't without controversy, though. In some cases, riders are zipping down sidewalks instead of the street, which is illegal.