Facebook has agreed to acquire cross-platform instant messaging app WhatsApp for around $16 billion (£9.6 billion).

The deal to buy the five-year-old company includes $4 billion in cash and around $12 billion in Facebook shares.

In the past few months, the topics of security and privacy have gripped the mobile industry. The humble SMS text message has been subjected to particular attention, both on its own and in association with smartphone apps.

John Murtagh, CTO at text message specialist Anam Technologies, explains more about the risks involved with SMS, the challenges for mobile network operators and the solutions that can protect consumers.

After catching up with last week's Microsoft announcement about new CEO Satya Nadella, we go on to talk about big changes for Brightstar and Sony as well.

There's also mobile payment news from MasterCard and Weve, some patent agreements, a warning about second-hand smartphone sales, a forecast of mobile data growth and a report about app developers.

App research specialist VisionMobile has published the latest version of its Developer Economics report, providing insights into mobile application development worldwide.

It estimates that 2.3 million people were mobile app developers in 2013, with 760,000 (32.9%) of them living in Asia and 680,000 (29.7%) in Europe.

This week's podcast starts with Lenovo's purchase of the Motorola Mobility smartphone business. Was it a good deal for everyone?

We also talk about network infrastructure sharing in the UK, mobile malware, 3G coverage, misleading apps, mobile advertising, Samsung's retail plans and global tablet sales.