[DanBC]

People keep doing dating type websites. That market is frighteningly full. But I'm surprised people haven't seen the state of the "penpals for prisoners" market - there are lots of websites and they are all, without exception, appalling. Not just a bit clunky, but really really bad.

To turn that from a dull idea (it's been done, it just needs to be done better) you'd add in some human rights stuff, and some prisoner reform stuff. If you wanted to push some boundaries you'd use it to include schemes that befriend, and monitor, paedophiles.

(http://www.bbc.co.uk/news/uk-england-11755527)

Add in some work / education programmes (using some disruptive technology to deliver the education; because you have a captive market.) and you've got a nice socially aware start up.