I don't think a large government has tried yet; this would create an interesting incentive for one to do so. See Operation Bernhard https://en.wikipedia.org/wik

I don't think a large government has tried yet; this would create an interesting incentive for one to do so. See Operation Bernhard https://en.wikipedia.org/wiki/Operation_Bernhard https://en.wikipedia.org/wiki/Operation_Bernhard with "on the internet" appended to it.