In this sentence "curbing out" reads strange. I can't find much on Google. It doesn't appear to have any meaning beyond "curbing", "inhibiting", and I am not sure the tag-along preposition "out" adds anything semantically. Is "curb out" idiomatic at all? Is it an Australian English phrasal verb?
This Antipodean phenomenon has a strong presence in workers’ rights and political debate, especially when it comes to curbing out cigarette smoking. (source)