Social media has enabled crowd behavior to become independent of time and location. Examples include the 2011 Egyptian revolution which relied on Facebook and the 2011 London riots which spread via social media. Virtual crowds can belong to multiple online communities simultaneously through tools like Twitter, Facebook, and Reddit. These tools also allow information to spread virally very quickly with little direction. Businesses must track social media buzz using tools like Twitter, which allows public messaging and searching of tweets. Third party tools provide additional search capabilities and access to older tweets.