Is internet privacy a problem?
Would you let your boss read all your emails - and that means your personal ones too? Would you let your mother know precisely where you are every moment of the day? Would you let the man who drives the bus have the number and security code of your credit card? I thought not, yet most of us choose to share all this information and much, much more with complete strangers every single day via the internet.
The issue of internet privacy has been in the news because Google has just changed its rules to allow information to be shared across all its services. But Google isn't the only internet service busy farming your data - lots of them are at it.
So, is this an invasion of our rights? Justin Rowlatt discusses the intricacies of the internet privacy debate with Jeff Chester, head of the Center for Digital Democracy in Washington and Simon McDougall, managing director of Promontory in London.
Listening to that discussion may make you wish there was a delete button that would allow you to just wipe away that great trail of online information you have left behind you. If so then Frank Ahern is your man. He's the self-styled "digital hit man" - an online asassin who claims to be able to rub-out - or at least disguise - unwanted online identities.
He's just published a book titled The Digital Hit Man, sharing his secrets. But, Justin Rowlatt asked him, should we really be so worried about releasing a bit of data onto the net?
Plus hybrid cars have become very familiar but but how about a hybrid boat? An Australian company has developed what it is calling the world's first solar-powered ferry fleet. Diesel motors do most of the work but it has electric engines too as Katie Hunt in Hong Kong discovered when she set sail on one of them.