Cloud physics vertically developed clouds, the cumulonimbus type is the tallest and can virtually span the entire troposphere from a few hundred metres above the ground up to the tropopause. It is the cloud responsible for thunderstorms. Some cirriform clouds can form at very high to extreme levels above the troposphere, mostly above the polar regions of Earth. Polar stratospheric clouds clouds are seen but rarely in winter at altitudes of 18 to 30 kilometers, while in summer, noctilucent clouds occasionally form at high latitudes at an altitude range of 76 to 85 kilometers. Homospheric types determined by cross-classification of forms and
Timeline of events associated with Anonymous Timeline of events associated with Anonymous Anonymous is a decentralized virtual community. They are commonly referred to as an internet based collective of hacktivists whose goals, like its organization, are decentralized. Anonymous seeks mass awareness and revolution against what the organization perceives as corrupt entities, while attempting to maintain anonymity. Anonymous has had a hacktivist impact. This is a timeline of activities reported to be carried out by the group. According to radio host Hal Turner, in December 2006 and January 2007 individuals who identified themselves as Anonymous took Turner's website offline, costing him thousands of dollars in bandwidth bills.