Speaking at Scotland Yard yesterday to discuss police plans surrounding the G20 Summit and associated demonstrations, Metropolitan Police commander Simon O'Brien said that tapping into social networks is a "key area of our intelligence gathering".
"That is where we are picking up a lot of our intelligence about numbers and what certain groups are aiming to achieve," he said.
The protests start on Saturday with a 'Put People First' march about the financial crisis, which is being organised by unions and anti-poverty groups. But the Met's biggest concern is demonstrations taking place on 1 April, the day before the G20 Summit begins.
Wednesday will see an anti-war march, environmental protests and a 'Financial Fools Day' demonstration organised by an umbrella group called the G20 Meltdown.
Marina Pepper, one of the organisers of the G20 Meltdown, told CNN that the group is using Twitter to help co-ordinate the protest.
"Our stance on predictions of riots [is that] we come in peace. But if we are attacked by police we will defend ourselves. Can't say fairer than that," said Pepper in a Twitter blog.
Meanwhile, two Facebook groups linked to the protest have clocked up nearly 2,500 members, one of which displays a flyer that reads 'Burn a Banker!'.
"Their tax-dodging, bonus-guzzling, pension-pinching, unregulated free market world's in meltdown, and those fools think we're going to bail them out," said the group administrator on the site. "At 12 noon, April 1, we're going to reclaim the City, thrusting into the very belly of the beast: the Bank of England."
The G20 Summit is an annual consultation at which finance ministers and central bank governors of 19 countries discuss how to promote financial stability. This year the meeting is dominated by the increasing economic crisis.
UK host Gordon Brown plans to urge G20 leaders to agree a $100bn (£69bn) fund to drive global trade, but tensions have been heightened by Luiz Inacio Lula da Silva, the president of Brazil, who argues that the crisis clearly originated in the developed world.
The Summit will also be US president Barack Obama's first trip to the UK.
A statement from the Metropolitan Police said that the force is "monitoring all information relating to planned protests and advertised actions, including open source information".
Cotton seedling freezes to death as Chang'e-4 shuts down for the Moon's 14-day lunar night
Fortnite easily out-earns PUBG, Assassin's Creed Odyssey and Red Dead Redemption 2 in 2018
Meteor showers as a service will be visible for about 100 kilometres in all directions
Saturn's rings only formed in the past 100 million years, suggests analysis of Cassini space probe data
New findings contradict conventional belief that Saturn's rings were formed along with the planet about 4.5 billion years ago