I'm a security expert and these are the best ways to protect yourself from phone theft hell in London

Niall McNamee was travelling on the London Underground when a thief on the platform expertly snatched his phone from his hand just as the train doors closed. But that infuriating loss was just the beginning of his problems. Because two days later the 30-year-old actor discovered his bank accounts had been drained by £21,000 — including a £7,000 loan that thieves had audaciously taken out in his name.

"It used to be that people stole a phone so they could sell it," Mr McNamee later told the BBC. "Now it seems they are stealing phones so they can get into all of your data and take money."

And McNamee is not alone: in the UK there are now an estimated 200 such snatches every day, according to Home Office figures. London is Europe’s phone theft capital. But the problem is bad everywhere across the continent— and it’s getting worse.

So what can you do to protect yourself?

I work in mobile phone security and the bad news is that there is currently no tech-based solution to all this. Because obviously a phone snatcher can’t be blocked like a number can.

So yes, as the police in all these cities will tell you: take care. Don’t walk around with your head in your phone and your phone on display. Don’t make yourself a target.

But, of course, however much we intend to stick to this good behaviour guidance, there are always reasons why we don’t. You’re just coming out of the underground and you want to check your WhatsApp to see if your friend is on time. And, in this moment, you have made yourself a target. We all do this, inevitably.

But the good news is there are a couple of easy hacks to protect yourself from the worst of this, simple preventative steps you can take to stop yourself ending up £20,000 down like poor Niall MacNamee.

First and foremost — make sure your phone locks as quickly as possible.

Set your screen lock to come on in the minimum time available. On an iPhone this is currently 30 seconds. On some Android handsets it can be as short as 15.

And why is this basic step so useful?

Because the muggers are usually perched perilously on the back of a speeding bike — or they are on foot and running.

And they want your phone to be active to be able to rob you easily. If it’s still unlocked once they have made their getaway then they can reset the PIN and mess about with it at their leisure, getting into all your apps, intercepting those one-time passwords, two-step verifications and other protections that will no longer work.

But if by the time they’ve ridden around the corner or sprinted out of the station they find the phone has automatically locked then in all likelihood they will just give up on trying to ruin your life by cleaning you out financially. Instead they’ll move on to the next guy whose screen lock setting is a more sedate two or three minutes. And your phone will just be sold rather than ransacked.

And the other step to take today? Activate facial recognition on as many apps as your phone allows. Particularly banking or finance functions. And why? Because the requirement for your face and not the thieves’ will slow them down some more.

Then finally, there is one key thing to remember if you ever are a victim — and to do as soon as you possibly can: borrow someone’s phone and report it.

Then call your mobile network supplier and report your number and phone as stolen. This will see your number added to a lost and stolen database run by GSMA — the global trade association for mobile phone companies. And, crucially, the mobile network will also block your sim — making the network inaccessible from your handset. They should do this immediately and this will greatly inhibit the thieves’ timeframe for further criminal activity on your account.

So that’s it.

The phone companies are currently looking at more tech-based solutions: sensors that lock a phone when they detect that it may have just violently changed hands. But until such solutions are rolled out, this strategy is the strongest protection you can get.

You’d be mad to walk around any city without it.

Fergal Parkinson is a co-founder of mobile security specialist TMT ID