I was referring to things which may consider unethical, such as selling illegal drugs, prostitution.
Aha. Well - in all honesty - it's unlikely that anyone doing something 'small' could ever legally do it in terms of complying with the tax law and so on. A good example is teaching - virtually no Polish teacher giving private lessons will declare the income.
When small business consultation is privately done under the table, can the Polish government easily detect it?
It depends. From what I gather, the government doesn't tend to do much to catch people, but rather relies on reports from jealous competitors/neighbours to find the fish worth catching.