MTS

MTS is a mobile network operator in Russia, Ukraine, Armenia and Belarus with over 106.5 million subscribers in 4 countries as of 31 December 2017. As of 2017, MTS had the largest market share of 31% in Russia and is the largest mobile network operator in Russia with 104.7 million subscribers. On September 17, 2019, it was revealed that a storage device containing 1.7 terabytes of information related to MTS was exposed to the public internet in a data leak.