It's interesting to note that Marx's concept of exploitation (which is a much, much broader one than the examples you're using here, though they certainly quali

It's interesting to note that Marx's concept of exploitation (which is a much, much broader one than the examples you're using here, though they certainly qualify) does say that it would be within the best intersts of the working class as a whole to rise up against such a system and indeed to illegalise (well, prevent in some way) hiring.