It's more about the second hand market than piracy in my opinion.
My own personal theory is that the developers/publishers are losing far more money from the second hand market than they are from piracy.
The great majority of 'pirates' wouldn't have bought the games they downloaded anyway, whether it's because they have no money, don't like the game, download it for the thrill or just want to have what everyone else has pre-release.
Taking this into consideration, it's logical to assume that the actual revenue lost from piracy is not nearly as high as you might think. One download rarely equals one lost sale. Even if the downloader has disposable income, it is often already allocated to other things which leave them with little to spend on the game. For many, this would certainly be influenced by the fact that the game may be 'easy' to get for free, where as the other things they spend their money on are not so easy to get hold of.
Contrast this with the second hand market where the majority of purchases do actually equate to a 'lost sale' and therefore lost revenue for the developers/publishers.
If you walk into Game and want to buy a brand new £35 game but also spot it in the pre-owned rack for £20, which one do you buy? Which one do you think most people will buy?
Second hand sales hurt developers/publishers far more than piracy, because they take the money that was certainly earmarked for new games and it gets spent on a second hand product which the developers/publishers see no revenue from. This is far worse than piracy and I'm quite sure that most companies in the gaming sphere are well aware of this. It's just a whole lot easier to restrict the freedom of consumers in the name of piracy than it is in the name of stopping the second hand market.
Of course there is plenty of room for discussion on this subject and I'm sure some will disagree with me, but that's my very basic reasoning for believing that moves like this recent one from Ubisoft is more about killing second hand sales than it is about killing piracy.