In recent months, Amazon Web Services has found itself criticized by Greenpeace for its environmental sustainability. The company’s data centers are apparently inefficient compared to its rivals. Greenpeace’s Senior Energy Campaigner, David Pomerantz, went a step further, openly questioning the energy practices behind the Amazon Fire Phone's cloud services. The mobile device is a "stone aged machine,” he claimed. Amazon’s response was expectedly terse - Greenpeace was being "inaccurate" and ignoring key data already provided by the company. This was the second time in 2015 in quick succession that Amazon has had to defend itself.