Fact "H1Bs cannot do their own business in US". So checking the legal limit with below scenarios.
1. Can a H1b, while working for H1 employer, work for non US employer using options like work from home or other internet technologies and earn in their local currency without further documentation?
2. Does anything changes if the non US employer has clients in US and the person in above position actually work with those clients under the payroll of non US based organization?
3. Does it cross the legal H1B limit if we assume the H1b person in scenario 1 and 2 is also the owner of non US company and earns in local currency not USD?
1. In my view, no.
2. No. The critical thing is that the work is being performed on US soil.
3. I believe this too would be illegal under immigration laws.