The idea
This concerns those who seek to justify interfering with innocent activities in the name of security. As an amateur photographer I am aware of how often my fellow enthusiasts have been harassed by law enforcement officers when doing no more than taking photographs of public buildings or public areas such as Trafalgar Square. The presumption seems to be that the person involved is either a paedophile or a terrorist and these officials frequently assert that a prohibition exists when it does not. In this case, rather than removing a law, it would be necessary to make it clear that such interference with lawful activities will not be tolerated. It should also be permitted to photograph police officers as this is usually intended to add colour to pictures of London etc.
Why is it important?
Busybodies should not be indulged in their habit of interfering with law abiding citizens in the name of spurious regulations which often do not actually exist