[Closed] Why is peaceful protest considered 'Civil unrest' by our govenment?

I just came across this article
http://news.bbc.co.uk/1/hi/uk/7905172.stm

"Police are preparing to face a "summer of rage" in the UK as people join protests over the economic downturn, says a senior Met Police officer.
"Known activists" were likely to foment unrest, with the recession creating more "footsoldiers" to join them, Supt David Hartshorn told the Guardian."

Surely there is only likely to be significant unrest if people are genuinely unhappy and have no other effective way to be heard? And scarily what constitutes a "known activist" - a member of Liberty civil rights? A left wing polititcian? A football thug? The policemans reaction seems somewhat over the top.