What is the source for your claim about birth certificates?
You are lazy.
There are many sources.
I'll give you one, then stand by as you try to explain it away.
http://www.cis.org/identitytheft
This Backgrounder examines illegal immigration-related document fraud and identity theft that is committed primarily for the purpose of employment. It debunks three common misconceptions: illegal aliens are “undocumented;” the transgressions committed by illegal aliens to obtain jobs are minor; and illegal-alien document fraud and identity theft are victimless crimes. It discusses how some community leaders rationalize these crimes, contributing to a deterioration of the respect for laws in our nation, and presents a variety of remedies, including more widespread electronic verification of work status (E-Verify and the Social Security Number Verification Service) and immigrant outreach programs to explain the ramifications and risks of document fraud and identity theft.
The findings include:
•Illegal immigrants are not “undocumented.” They have fraudulent documents such as counterfeit Social Security cards, forged drivers licenses, fake “green cards,” and
phony birth certificates. Experts suggest that approximately 75 percent of working-age illegal aliens use fraudulent Social Security cards to obtain employment.
•Most (98 percent) Social Security number (SSN) thieves use their own names with stolen numbers. The federal E-Verify program, now mandated in only 14 states, can detect this fraud. Universal, mandatory use of E-Verify would curb this and stop virtually 100 percent of child identity theft.