Suppose I create a new coin that I also call Nano. I create a bunch of bots and websites and post on message boards so it looks like my version is more popular and has more participants.
There are people and organizations attempting to do this with Bitcoin right now. How do people tell the difference? Sometimes they don't and they get scammed.
You won't. This is why Bitcoin is valuable since it has stood the test of time and has gained more acceptability. Nanos and other nonsense coins are just trying to attack the emperor in the hope that they come close to it and thus make the speculators a lot of money.
