The underlying data in the chart come from a database called LexisNexis which, by all accounts, is an indispensable and well respected resource for looking at media coverage over extended periods. Unfortunately, it's a fairly expensive subscription only service so it's not something I have personal experience of (but my birthday is coming up so if anyone is feeling generous....).
What it shows is the number of times the word(s) 'scrounger(s)' appeared in the UK press from 1994 to the present, with a huge unprecedented rise coinciding with the arrival of the coalition in power. Understandably it has had wide circulation in political circles, not least of which because of the sustained campaign against benefit claimants in parts of the print media and the government's willingness to stoke the flames by selective, and in some cases, deceptive use of official data (See here. Hang your heads in shame, Iain Duncan Smith and Grant Shapps). The picture the data give of trends over time is quite alarming but not really surprising. Say something often enough and people start believing it. Media manipulation is nothing new and a constant drip, drip, drip of 'scare' stories have resulted in negative attitudes towards benefits and claimants being legitimised and made respectable. Once the ground has been prepared, it's so much easier for the ruling party to bring in punitive measures. After all, they are all scroungers, aren't they?
One thing I find puzzling is why negative coverage finds such a ready audience amongst the Great British Public. Whatever the explanation, I've got the persistent feeling that if it's worth someone's while to spread misinformation, it's worth my while to try to set the record straight insofar as I can within my limited sphere of influence.