Racism is believing that all members of a race have the same (usually negative) characteristics and using discriminatory or abusive behavior towards them. Doing this online is cyber racism.
Of course we should all look out for scammers and protect ourselves... but please educate yourself before you start treating people differently based on where they're from.
I don't have more recent stats, but in 2009 IC3 (the Internet Crime Complaint Center) reported that the United States had the highest internet fraud rate, with 65.4% of reported cases coming from within the U.S. The U.K. was right behind them at 9.9% and Nigeria behind them at 8%.
And before anyone says that it used to be Nigeria was the worst and things have changed recently (this comes up every time I post this anywhere online). In 2008, 92.93% of internet fraud came from the U.S. and Nigeria wasn't even on the top 10 list.