Some numbers, from the poet 'Francis Crot':

Highest estimated cost of riots: £100 million.
Tax avoidance by Vodafone: £6 billion.
Tax spent on Libyan intervention: £1 billion.
Tax money spent in Iraqi conflict: £4.5 billion.
Tax money spent in Afghan conflict (up until 2007): £7 billion. Still rising.
Tax avoidance in 2010 by “richest” (?) people in UK: £7 billion.
Tax spent on interest for bank rescue package: £131 billion. Still rising.
Total MP expenses bill (2007): £87.6 million. Still rising.

Technically, we could afford to have a riot for everyone!

You can quibble about the figures (the Financial Times has put the cost of the riots at more than £200 million), and they don't quite add up (assuming 'everyone' means the 60 million people in the UK), but the general point holds – not to mention that the government is hardly in a position to accuse anyone else of not being able to count.