So what does a rapist have to actually do, to serve a life sentence? If well over 100 women aren't enough, how many women does one man have to rape, in order to get a life sentence?
Fortunately the law has changed since Worboys was sentenced. He was sentenced under a particularly nasty and devious law introduced during the Blair years and completely characteristic of him.
He was sentenced to an 'indeterminate sentence' with a minimum term, which was a particularly manipulative bit of legislation.
Basically what it meant was that at the time of sentencing the government could look tough by saying 'we've given him an indeterminate sentence so he might be in for life'. Actually, they knew full well they probably wouldn't serve much more than the minimum term but hoped that when the outrage died down they could release them on the quiet. Baby P's mother was another sentenced in the same way.
It was a sham designed to make the Labour government look like they were tough on crime when actually they knew it would be used to give really short sentences but avoid an outcry.