I don't understand the problem. You're ill, you claim benefit - is this not the very nature of the system?
Yes, some people defraud the system, but where there's money there's crime, it's a fact of life. The estimated cost of benefit fraud doesn't even begin to approach the level of revenue lost to HM Treasury though "legal" tax avoidance schemes.
The combined cost of fraud
and error in the benefit system is somewhere between £1-3 billion. The revenue lost through tax avoidance stands at around £15 billion.
http://citywire.co.uk/new-model-adviser ... ud/a378274