There is no difference between GG and MSN
One in Polish the other in English ;0)
Facebook is overall more secure. You can really look at people's profikes without first adding them as a friend. the same with sending messages.
You can send messages to people who are not on your friends list on FB, you can also view a persons profile if they are stupid enough to have that option, most only give limited access to none friends. FB is a bago poo most of the time, random people who you havent seen for years and never want to see again wanting to be your friend...no thanks!