employment

hi everyone,
i wonder if anyone ever hears anything like this:
my friend told me that if you fake some personal information, such as age, race, name... when you register on some web sites, like facebook, linkin, and skype, your companies can or will terminate your employment if the companies find out that the information you input into the web sites does not match what your employers have in the database. in addition, even though you can provide the official documentation to your employers when they need to verify your information. is it true? because it doesn't make any sense to me.

p.s. i first posted in other area in this forum, but nobody response. hopefully i will get some responses here. thanks!