After doing the survey, I can smell the bias almost every question asked.
As with any research based work you do at university level, if it's seen as biased you better have a really good reason to be able to still use it as supporting evidence for you opinion on a idea or statement.

Currency is not the problem, it's the people involved that is. You don't see people blaming the British pound or US dollars since it sometimes is use to buy drugs, buy weapons or hire hookers. Some is illegal or at least controversial, the people are doing the act, the medium of currency doesn't matter that much.