Spammers are hard tribe, and obviously follow the latest technologies, thus targeting popular at the time communication services, to distribute "product" you. There are a recent example:
Yesterday to Viber users in the country has been sent spam message notifying that from this Sunday (17.01.) Viber will begin to charge their services. The message invites recipients to disseminate information to their contacts, as this will keep the free services of Viber, as will be noted as active users.
Viber is Free!
Viber announced that the information in the spam message is false and its source is not Viber. Viber lets everyone in the world to communicate free underline the company. Messages, calls, entertainment games and sharing content via Viber with friends and family is unlimited worldwide. Viber users can safely continue to enjoy free communication application in the future, it reads more official statement from the company.
Viber is Free!