"I lost 5000 Euros when my phone number was hacked and re-used on another sim card," says Jack Monroe. The culprits then successfully received her two-time verification information and obtained her bank and cash records."I was already concerned about the safety and had several steps in check," said Jack in a tweet. The industry was not able to address the "sim-jacking," says a privacy campaigner. The blogger expressed her anger in a tweet when she was told, 'although she would get her mobile number back in no time, the amount stolen will take time to refund.' "The cash taken has cost me very much - I'm a self-engaged freelancer and I have to work for every cent that I make," she tweeted.

The food writer is recognized for her cost-effective recipes and her support for campaigns against poverty. Sim-jacking, or Sim-swapping, is when culprits switch a mobile number with another Sim and use it as their own. This is done by criminals pretending as a consumer who wants to shift to a separate mobile service provider but doesn't want to change the phone number.

While personal information is required before requesting a sim transfer, the information is sometimes already available on the internet. - In this case, Ms. Monroe's date of birth, for instance, was retrieved from the internet. In other cases, the shop keepers or sim providers are often tipped for sim-jacking.

The first sign of sim hijacking for the victim is when their phone stops functioning. "The cases of sim-swapping in England are rare but there have been instances in other parts of the world. The industry is unable to combat the problem of sim-jacking," said Pat Walshe, Director, Privacy Matters, to BBC. The task of sim swapping is not common but one can do it easily if they want to, says Pat.

If ever caught in sim-jacking, the victims should always report the incident to their mobile operator or the ICO (Information Commissioner's Office). "The case should now push the ICO to inquire whether mobile operators and shop owners are actively following the protocol to protect services and data under telecommunication privacy laws," said Pat. The Global System for Mobile Communications, commonly known as 'GSMA' has made an alternative mobile identification verifier known as Mobile Connect. The ICO has been contacted by BBC, regarding the data theft problems.