A friend on Facebook was saying that the idea of wage theft is wrong because wages already are theft, the theft of surplus value from the worker. The thing is, can only be considered theft if you do not understand what is happening in wage labour. This is NOT a defence of capitalism and wage labour, but an illustration of how capitalism works and how it is 'fair' and 'just' and all those fine words that leftists like to talk about.

Every day you need $50 to pay for food, rent, travel, and so on, in order to maintain yourself as a productive worker. Therefore, the cost of your ability to work for a day is $50.

To pay for that need, you take up work in a window factory. The cost of your ability to work is $50, so you are paid $50 for your ability to work. Each hour at work, you make 1 window. Each window costs $50. So in your first hour you have made a product worth enough to cover the cost of your existence. However your ability to work all day was purchased, not your ability to to work an hour. So you continue to work for a further 7 hours, producing $350 of surplus value for the factory owner. The exploitation, the surplus value, is a result of a fair exchange.

If you decided that since you make $50 in that first hour, that you would instead only work for 1 hour and make 1 window, then you would need less energy, food, sleep, worse bedding, and so on to maintain your existence as a worker capable of 1 hour of productive work. That is, you would cost less than $50 a day, let's say you now cost $30, and therefore your wage for that hour would be $30, but you would still make a $50 window in that 1 hour of work, and therefore make surplus value for the capitalist.

You would still be paid at the cost of your labour power, and it would not be theft. You agreed to work for a day in exchange for a wage which covers your daily existence. You performed the work and the capitalist paid you. A perfectly fair exchange.

This is entirely different to you making 8 windows in a day in exchange for $50, and the capitalist deciding "nah, I'm not gonna pay you for your day's work, I'm keeping that $50" which is what wage-theft is.

*the above ignores the non-labour costs involved in making the window coz irrelevant to the point I'm making, as well as the reality that the cost of your labour power may be higher than your wage, also coz irrelevance*