I'll ignore them, they aren' worthy of your time and effort because these type of people are close minded and no matter how good you educate them, they won't accept it, it's not my lost anyway its there's. For me, what matters most is that I know bitcoin isn't a scam and if people will insist it's a scam then let them be, i'll do my thing and I know they will only swallow there words and realize that bitcoin is 100% legit and very far from scam.