Afterword

ThimphuTech was the first technology blog in Bhutan. We started writing it in 2009, just as broadband and mobile internet started to take off. (Although internet in Bhutan was launched in 1999, it was either super-slow or super-expensive, and was only used by a selected few).

In the blog, we wrote about technology and food, but also about plenty of other stuff. The blog became popular and influential in Bhutan. A companion bi-weekly column -- Ask Boaz -- was published for many years in the Kuensel, Bhutan's national newspaper. (The complete Kuensel columns are available as an ebook, Blogging with Dragons).

We stopped updating the blog when we left Bhutan in 2014, but the information within the posts can still prove useful, and thus we decided to keep it online.

We thank all our readers.
Tashi Delek,
Boaz & Galit.

Monday, September 3, 2012

Bhutan Telecom's new MCA service: Useful, but undocumented "feature" invades privacy

Bhutan Telecom recently introduced (or rather, re-introduced) the free Missed Call Alert (MCA) service. When you subscribe to the service, you don't need to worry about missing a call when your phone is switched off (or out-of-network). Once your phone is re-connected to the B-Mobile network, you will receive an SMS for each call that you missed (including international calls). Here's a sample SMS that you receive from the service. Note: the inconsistent capitalization is in the original message.
You have Missed Calls from +97517XXXXX Called At 10:40 On 03/09/2012.It May be important to call back.
This is an important and useful service. It also benefits Bhutan Telecom: sending an SMS is virtually free for the mobile operator, but the service will encourage people to make more calls. Here's how the service is described on BT's website:
Bhutan Telecom is pleased to inform all our valued customers that the Missed Call Alert service has been commissioned. Subscribe to FREE MCA and capture all the important calls you have missed while you phone is switched off or out of reach.
All Postpaid users will be registered for MCA by default.
Bhutan Telecom is so confident about this service that it is enrolling some users for this service without even asking for their consent. There is, however, a privacy issue with this service which BT forgot to mention. When you subscribe to MCA and someone tries to call you, in addition to the SMS you receive, the person calling you - the caller - knows when you switched your phone back on. How? Apparently, the caller also gets an SMS. Here's a sample message received by a caller. Note: Again, the inconsistent capitalization is in the original message.
You tried to call +97517XXXXX at 10:40 on 03/09/2012. He/She is back in Network at 10:43 on 03/09/12. Try Calling Again.
This "feature" - the SMS received by the caller - is not mentioned on BT's website.  Basically, the caller now knows that (1) you're back on the network (2) you received a message about the missed call. There are various privacy issues with this feature, as well as some various odd situations this can create. For example, it allows people to follow you. Say you're out of Bhutan. Once you return and switch on the phone, anyone who called you during your absence will receive a message. Good or bad?

Here's another example. Suppose you just called a secret friend whose phone is turned off. But you don't want anyone to know you dialed that person, so you delete his/her number from your Dialled Numbers list. However, if your secret friend has MCA turned on, once they are back on the network an SMS from B-Mobile will suddenly be sent to your phone, revealing that you tried calling this secret friend! I'm sure you can think of some unpleasant situations this can cause...

By the way, B-Mobile is using two different recorded messages for disconnected phones, one for MCA-subscribed phones, the other for phones that are not subscribed to the service. This means that a caller can know whether you're subscribed to the service! Here are the messages:
  • The number you're calling cannot be connected at the moment. Please try again later. (Subscribed to MCA)
  • Subscriber switched off. Try after some time. (Not subscribed to MCA)
Apparently, there's a tiny difference between after some time and later...

To subscribe to the MCA service, send SUB to 707. To unsubscribe, send UNSUB to 707.