More than 5,000 police officers are taking part in a crackdown on stolen mobile phones and other personal thefts after a surge in the crimes in the past year.
Figures have shown a rise of 12% in personal theft in London, which Scotland Yard said is fuelled by an increase in the number of phones being taken, compared to 8% nationally.
The force said statistics show around 10,000 phones are stolen per month in London, accounting for nearly four in five thefts from the person. Half of the handsets taken are iPhones.
Today spot checks will be carried out and police will visit pawn shops in what is the fourth operation of its kind in the capital so far this year. The three previous operations, called Big Wing, have led to around 1,700 arrests.
Specialist teams including dog handlers will also be involved in today's crackdown.
Commander Stephen Watson, leading today's operation, said: "Mobile phone related crime is a high priority for the Metropolitan Police. Work continues day in and day out to target those responsible and the networks they use to sell on stolen property, but big, highly visible operations like today play a major part in the fight against crime.
"Crimes like burglary, robbery and theft have a huge impact on the people who are victims. The operation aims to stop criminals stealing in the first place but registering your phone can really help us get your property back to you and bring successful prosecutions against those who are targeting these high value devices.
"We would also ask the public to take extra care of their valuables. Many of the thefts are taking place during the day in shops and cafes but at night the problem moves to bars and nightclubs."
Men are more likely to be victims of robbery, while women are more likely to fall prey to thieves.
The most common victims are young professionals aged between 20 and 30, targeted while they are out socialising or using public transport.