[pierotofy]

I agree with you on being cautious. I don't think it's a simple matter and yes there could be negative, unintended side effects. I think it would at least worthy of consideration and study, as lots of FOSS has many of the characteristics of public infrastructure and suffers from the free rider problem. Make the legislation narrow in scope as to limit potential downsides, evaluate results after a few years, go back if results were not as intended, or change it based on results.

Make the tax voluntary, give incentives to companies for paying it and keep the definition of FOSS.