Police in downtown Los Angeles have seen cellphone thefts soar as smartphones like the iPhone become easily turned into pay-as-you-go phones.

In the first quarter of this year, thefts of cellphones increased 32% in the downtown area. In the one-mile-square area of skid row, the increase is even more pronounced, said Los Angeles Police Lt. Paul Vernon.

Individuals reported 54 cellphones taken in crimes within skid row in the first three months of 2012, compared with 115 during all of 2011.

"If that trend continues, we'd see an increase in of 144% by the end of 2012," Vernon, commanding officer of the Central Detective Division, said in a news release. "It made us ask, what's going on?"

The downtown Fashion District registered 27 cellphones stolen in 2011, and 10 were reported taken during the first quarter of 2012. Near 5th Street and Broadway, which has seen an upswing in street sales of prescription pills, seven phones have been taken this year, compared with 13 for all of 2011.

"A crook can snatch an iPhone, replace the SIM card with one from a pay-as-you-go phone and have a brand-new, latest-generation phone for himself," Vernon said.

In past generations of phones, the service could be turned off and the phone, for the most part, would be useless, he said. On newer phones, if a pay-as-you-go SIM card is put in, there is no record of the user with a service provider.

"The phone companies don't really care about this flaw because if the phone gets stolen, the victim will buy another phone, and [the] crook will keep using the one he stole," Vernon added.

Police said phones are commonly being snatched from restaurant tables, libraries and nightclubs as people leave them unattended.

Men and women were equally likely to have their phones taken, according to the most recent crime statistics for downtown.

In 2011, cellphones were reported taken in 12% of all the robberies, thefts and burglaries combined. They were the most stolen item, after money.