No, you can't say peoples when you're referring to a bunch of people. That's a blatant mistake. The word people is already plural. The singular form of people is person. So, it's one person if we're talking about a single individual and it's people if we're talking about more than one individual.
However, you can say peoples in situations when you're talking about different ethnic groups. In this case, a people basically means a nation and peoples means more than one nation (ethnic group is a better definition though because the word nation is rather a political concept). So, it's neither a mistake nor an abbreviation. It's perfectly valid English grammar.
The native peoples of Canada number more than 40 ethnic groups.