Facebook is one of the most secure Social Networking Sites, which makes it almost impossible to just look in to anyones profile.
You can see someones facebook profile under certain conditions :
1> The person has listed you as a friend, or
2> The person who’s profile you want to see must be in your friends network, (i.e. one of your friend must be in their list) and should have given permission for the first network to view their details, or
3> The person who’s facebook profile you want to see must be in the same network and the privacy settings permission should allow everyone in the network to see more details on their profile.
These are the only ways you can see someones facebook profile, who is not in your friends network.
If you click on someones profile and are unable to see any details about them, it means that you do not fall into any of the three cases mentioned above.
If you desperately want to see someones facebook profile then you can try something like joining any of the networks they are a member of and see their profile, but remember facebook gives enough freedom for users to adjust their settings in such way that they can make it impossible for strangers to view their profiles !