Yes, there are lawyers who for a price give them jobs, and the promise of Immigration. And very often deliver. But what if the lawyer gets caught? CIS investigates every case that the attorney had represented, and investigates. So people who get their green card by dishonest means can loose it after several years, when they are settled here and gotten used to the US lifestyle. Please remember , if the attorney does something illegal for you, he or she is probably doing this for many others. And eventually the CIS will catch on, and investigate the lawyer. And if your case is found to be a fraud, you will be banned permanently from the United States.
Thus the stakes are high.