First and foremost, it is important to know that there are no special programs and web sites supposedly giving you the opportunity to see hidden friends on someone else's Facebook page. All the tricks of swindlers, who have only one aim – to obtain username and password from your social network or to "extract" a certain amount of money to "infect" a computer virus, that is, to cause certain harm to the person to their interests.
There are ways that allow you only to learn about the hidden friends Vkontakte on someone else's page. The first of these will help only if you suspect a person has hidden privacy settings for certain friends that you know. In this case, just go to the page for these people and look at their list of friends the man who was able to hide them. If it is in the list, then just hid them for some reason. However, it can also be hidden, so the method is not entirely accurate.
Some users have noticed an interesting pattern, which can be useful if you want to see how many friends hidden from the user. Go to the list of his friends and look at their number. Remember figure. Now set the list so that it displayed at first only men, then only women. Remember the two numbers and then add them up. The resulting value may exceed the initial number of friends of the user. This may indicate two things: the difference shows the number of friends or newly retired users (as well as people who are not marked in the personal information gender).
Pay attention to the activity on the page you are interested in the user. If it is going to appear suspicious "likes" and comments from people other than his friends, perhaps they are just hidden, but accidentally gave myself these actions. The same applies to the person, that you check. If he suspiciously often active on someone else's page, that user could be his hidden friend.