the secretary will disavow any knowledge of your actions

Via Slash dot, we learn that an upgraded e-mail service not only has a self-destruct feature (among many other new options) but that activists are petitioning the company to disable feature for governmental and public entities, fearing that they could use it to hide or delete records, research and transactions it would rather not be the subject of public scrutiny.
What do you think? Perhaps for private and personal matters, it is useful to be able to choose an expiry date for one’s missives to regain the right to be forgot and not have everything inscribed in someone’s permanent dossier. Knowing, however, that governments lean heavily on their suite of hosting services to organise and conduct their online communication and store their data, it does seem at odds with the public interest to provide the means to maintain the integrity of public records and at the same time the ability to rubbish it.