如果按你所说无照执业是刑事案件，那么最好直接报告，不要要挟。

Extortion does not usually require that the offender threaten to commit a criminal act as long as the threat attempts to obtain money, property, or to force the victim to act against their will. For example, a threat to bring criminal charges or file a police report unless money is paid is still extortion, even though the offender may have every right to file a police report. By coupling the legal act with the illegal act of demanding payment to not act, the offender has committed extortion. Note, however, that a threat to file a civil lawsuit typically is not considered extortion even if that lawsuit is frivolous.

Read more: http://criminal-law.freeadvice.com/criminal-law/violent_crimes/extortion.htm#ixzz3fWdqFDIt
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如果上贴适用，最好不要要挟，而是直接报告。