The web site FatallyFlawed suggests that socket covers may actually be dangerous. Having reviewed the evidence I am inclined to agree.
Below are three videos made by FatallyFlawed showing the evidence.
The videos show how some socket covers can be inserted into just the earth hole in a mains socket. This disables the built in shutters exposing the live and neutral contacts. Other socket cover designs allow narrow objects such as a paper clip to be poked through the cover. It is then possible to make contact with the live mains connection.
So why are socket covers on sale?
In theory they prevent electrocution from objects being stuck into the socket holes. Now this might well be a very worthy idea in countries where the mains sockets do not have built in shutters. British square pin electric sockets have had built in shutters since the 1940s.
Watch the videos below to make up your own mind.