Two things are worth keeping a close eye on. First, the Lib Dem reaction to all this. Cameron's direct rhetoric probably won't sit right with some in the yellow corner, but their real concern will be one proposed element of the crackdown: allowing private credit firms to sift through the financial records and applications of suspected benefit cheats, and paying them according to how many fraudsters they nab. Already, Tories are stressing that these checks would be perfectly legal and in line with the Data Protection Act – but there could still be a clash over civil liberties.
And then there's the question of where all the money will go once it has been saved – if, indeed, savings are found. There are three clear options: i) claim it as cut to overall spending, ii) use it reinstate one of those spending items which are "not an intrinsically bad idea," but which would have been cut otherwise, or iii) let the DWP hang on to the money, perhaps to help fund IDS's wider benefit reforms. Cameron's language over the past few days suggests that number iii) might be on the cards – and let's hope so. Only radical benefit reform will tackle the deeper problems of the welfare system.