Here is a good article on why our current system to go after illegal aliens does not work and the simple solution from a state that has had it work and has reduced its illegal alien problem.
From the Tennessean article...
To date, the Arizona law also had not resulted in any penalties for business owners. There, businesses caught knowingly employing illegal immigrants twice in three years can permanently lose their business license.
Tennessee's law makes use of that same database optional and provides safe harbor to the employers who use it. The same safe harbor is granted to employers with a federally mandated I-9 — a form backed up by a combination of documents that attests to the worker's legal authorization to work in the U.S.
Advocates for tighter immigration policy, including the Washington-based Center for Immigration Studies, said the lack of successful cases show Tennessee's law isn't working.
"It just doesn't have any teeth," said Jessica Vaughan, a CIS senior policy analyst. "If the goal was to reduce illegal employment, then what's needed is something to compel every employer to participate in E-verify."