Well, I don't accept your definition of them as trade barriers.
When Ontario procured photovoltaic cells, it insisted that the company providing them had to create jobs in Ontario. Was that a good thing, in my view? Yes. When Ontario bought rolling stock for its transit system, it favoured a Canadian company. Was that a good thing? Yes. Would I like to see more of that in Canada? Yes. Do I have any complaint about the U.S., Europe, Japan, and China doing the same thing? No. Do I consider them to be trade barriers? No.