It's not good when government creates a situation where the only possible approach in order to succeed is to break the law.
Under the table, they're not paying taxes, insurance, permits etc. Besides that, they're collecting all the freebies the unemployed are so used to.
There was an article last week about the middle class not being a majority in the US anymore. The only chance for survival of the economy is for it to be advantageous to start and grow individual and small businesses legally.
When I lived in Cleveland I came across countless people who ran most of their business in cash. One was an Italian restaurant that only had 3 employees on their books. Here in West Virginia, we have personal property tax. So the state eventually gets its money when you buy something with your illicit cash.
Not saying you believe it, but this is the exact excuse I hear about illegal aliens. The government has made it soooo hard to enter legally, they must break the law in order to make a better life for their families.