> corruption necessarily envolves the government
False. [0] If the bank teller demands a bribe to let you withdraw from your account, that's corruption, even though they aren't working for the government.
> Corruption is the dishonest, fraudulent, or criminal use of entrusted authority or power for personal gain or other unlawful or unethical benefits. Corruption occurs in politics, business, education, media, and other social and economic fields.
That's either the crime of extortion (which is more broad than corruption) or failing to comply with official duties, which will likely result in firing. When I spoke of the crime of corruption, as expanded in a sibling comment, I was referring to a charge labelled "corruption". It seems, under US, there isn't a law against corruption per se, but against variations of fraud, extortion, etc. Unlike Brazil, for instance, where corruption is, specifically, a crime against the public administration. Still, my bad.
I concede that, outside of formal law, one can describe certain deviations of official attributions of private corps.' agents as corruption.