Despite widespread complaints and legal injunctions, Russia's largest mobile communications operator Mobile TeleSystems (MTS) continues to foist paid services on its customers without their consent or even their knowledge.

One of the most controversial schemes involves a promo action called Good'ok-bonus, which offers a tune-for-ringing-tone service via an SMS message to a subscriber.

However, a client who does not read and simply ignores it as ordinary spam gets charged anyway, by default, because the service operates on the "silence means consent" principle.

Last fall, the Saratov Province Prosecutor's Office examined MTS subscribers' complaints and ruled that the operator had violated the federal consumer rights protection law.

However, according to the Vedomosti business daily, MTS dismissed the ruling as "a recommendation that has no legal effect."

Last March, federal consumer watchdog Rospotrebnadzor challenged a similar service offered by MegaFon, Russia's third largest mobile operator, in the Republic of Komi.

However, not a single lawsuit has been filed yet, let alone class-action suit - most likely because the sums involved are not very large: For example, the Good'ok service cost about 50 rubles ($1.6) a month.

MOSCOW, February 25 (RIA Novosti)