The illegal employment of a foreign employee in Israel attracts both monetary and criminal prosecution for both the employee and employer.
The following is a summary for noncompliance in Israel:
Black stamp applied on the passport, banning entry to Israeli for up to 10 years and restricting entry to other countries (such as US)
Charged with a criminal indictment and possible imprisonment – both for the company and its managers
Black listing of company from the ability to apply for a future work visas.