"What people do in their own time is their own concern if it is legal. What they do in work time is another matter."
For an MP such categorisation is not quite as straightforward. How do you define work time and works computer for an MP.

This does not excuse reckless behaviour and gives rise to legitimate security concerns. Especially when GCHQ and NSA at menwith hill hoover up all electronic communications.

http://www.computerweekly.com/news/450297574/MPs-private-emails-are-routinely-accessed-by-GCHQ
Just emails? I suspect not.

The faux outrage here is very selective. Do you seriously believe only one MP is guilty?
I think the real danger highlighted here is the way a part of the executive has a means to pressurize the legislative.
(Just like over the pond)