This article is about the use of ungrounded power supplies with other electronic EQUIPMENT. Some types of devices do not require grounding plugs. This is often true with certain types of cameras and other devices that are used by themselves. Another another device could be a smart PHONE, which is not normally collected to the charger for a long period of time. So on ungrounded charger would not be considered a safety issue.
Laptop computers should have ungrounded power supply. Laptops can be connected to a local area network or to a telephone line by means of a modem. In either case there is a safety hazard if the equipment is not properly grounded. Also, there can be a PERFORMANCE issue. Some older laptops did not have grounded power supplies and they did not work well on dial-up modems publisher disconnect the power supply from the mains. I had an old IBM ThinkPad like that. The power supply what actually caused noise to appear on the telephone line. Like a that would not have occurred if the power supply had a grounding connector.


Here's a picture of a couple of power brakes and another of a couple of wall warts with the power brakes it's rather obvious that there are both to wire and three wire plugs for these devices the to wire plug is of course not grounded. Likewise with the wall warts. Obviously the to wire wall wart is not grounded. When using these type of power supplies be aware that cooking up such a device to your desktop or laptop PC may cause problems. Both performance problems and even damage of components. This is well documented elsewhere. I am not making this stuff up.
Comments welcome.