an unscrupulous trader/dealer一个不择手段的商人/交易商

Unscrupulous operators collect money from clients before vanishing without a trace.奸诈刁滑的经营者从客户手里收到钱后就消失得无影无踪。

These kids are being exploited by very unscrupulous people.这些孩子正在被无良之人利用。

the unscrupulous use of hostages对人质的无耻利用