AP: Four Greenpeace activists who clung to an oil rig off western Greenland using rock-climbing gear have been arrested after an Arctic storm forced them to abandon their protest. The four men — from the US, Finland, Poland and Germany — faced preliminary charges of violating a 1,650ft security perimeter around the Stena Don rig and trespassing by climbing on to the installation. The activists had been suspended under the rig since Tuesday to protest over British oil exporter …