I recently signed to the viber app to communicate with someone. However, I have noticed that it is a daft app as it allows you to be a contact to everyone who has your mobile number, unlike skype where they need your permission to become your contact and are able to speak to you and vice versa.
Anyway, I got an unwanted call on viber yesterday from someone who had my mobile number. I didn't want to speak to them so I did not answer the call.
They then sent me a message and so I read it and lo and behold, the stupid app let them know that I had done this, so they called me again.
It was embarrassing this time to pretend I am not available as I was just reading the message that they had sent me.
They have now sent me two more messages which I dare not read as that would indicate to them that I am around and just ignoring them.
What a stupid idea for an app to let the sender know that their message had been read and to allow people to contact you without your permission.