Tens of thousands of Mexico residents could have their cell phones cut off this weekend for failing to register their numbers under a government scheme to tackle organized crime.
Congress voted in the move last year in a bid to reduce widespread crimes, particularly extortion and ransom demands, carried out via untraceable cell phones.
If cell phone users fail to register by Saturday midnight, "their line will be suspended with no responsibility from their service provider," the Federal Telecommunications Commission said on its Internet site.
Out of around 79 million registered lines, just under 55 million had been registered by Thursday, or 66 percent, according to the commission.
Thousands rushed to register by SMS or on the Internet as the deadline loomed, but bottlenecks slowed down the process and some - including Mexicans without birth certificates and foreigners without Mexican identity numbers - were unable to comply.
The senate last week refused to extend the deadline, despite protests by telephone operators.
Spanish company Telefonica Movistar, with some 20 percent of the market, said on Thursday that it would not cut off unregistered clients.
But America Movil, with some 75 percent of the market and owned by billionaire Carlos Slim, said in a statement that it would suspend unregistered users.
Critics claim the law will be ineffective because criminals can easily register phones using other people's identities.