Pushed by recent legislation and smart disclosure initiatives, Personal Information Management Systems (PIMS) emerge and hold the promise of giving the control back to the individual on her data. However, this shift leaves the privacy and security issues in user's hands, a role that few people can properly endorse. Indeed, existing sharing models are difficult to administrate and securing their implementation in user's computing environment is an unresolved challenge. This paper advocates the definition of a Privacy-by-Design sharing paradigm, called SWYSWYK (Share What You See with Who You Know), dedicated to the PIMS context. This paradigm allows each user to physically visualize the net effects of sharing rules on her PIMS and automatically provides tangible guarantees about the enforcement of the defined sharing policies. Finally, we demonstrate the practicality of the approach through a performance evaluation conducted on a real PIMS platform.