There has always been a certain amount of fraud involved in family reunification visas—in the early 20th Century, Chinese would have what they called "paper sons," who they would tell the immigration authorities they had fathered overseas.

They may be having this problem in France, but with modern technology they've figured out a way do do something about it.

Now, President Sarkozy has again upped the stakes. Not only will incoming families face a higher hurdle, but an amendment quietly introduced DNA testing as a way to prove biological ties among them.France's open door is closing Christian Science Monitor, September 18, 2007