What brought AT&T to its knees?

A rash of online fraud in New York may have done what Operation Chokehold couldn't

Why did AT&T Wireless (t) halt online sales of Apple (aapl) iPhones in New York City the weekend after Christmas? None of the answers AT&T has given so far make much sense.

The new policy was first reported to The Consumerist's Laura Northrup by a reader in Brooklyn. In a blog entry posted Sunday afternoon, Northrup suggested that AT&T had found a novel solution to the city's data congestion problems: it had simply stopped selling iPhones to online customers in the metropolitan area. "The phone is not offered to you," a sales rep told Northrup, "because New York is not ready for the iPhone."

In an update later that day, Northrup posted AT&T Public Relations' inscrutable official statement on the matter: "We periodically modify our promotions and distribution channels." That didn't help.

The mystery deepened Sunday evening.

<!-- more -->

All Things Digital's Peter Kafka and John Paczkowski were told independently by AT&T representatives that sales had been halted due to an increase in "fraudulent activity" in the "high-risk area" -- specifically fraudulent orders made online. Indeed, the iPhone is still available at both Apple and AT&T stores in the city.

But as Paczkowski pointed out, you could still buy equally expensive Research in Motion (rimm) smartphones in New York City through AT&T's website. Apparently the BlackBerry was not quite as hot as the iPhone in the city this holiday season.

We await a fuller explanation from either AT&T or law enforcement officials.

Meanwhile, the whole situation has got Fake Steve Jobs -- whose Operation Chokehold protest against AT&T had no visible effect on the carrier -- chewing Ativans like they were breath mints and threatening to throw cars through the windows of AT&T headquarters.

UPDATE: By Monday afternoon, online sales were working again on AT&T's website.

[Follow Philip Elmer-DeWitt on Twitter @philiped]

All products and services featured are based solely on editorial selection. FORTUNE may receive compensation for some links to products and services on this website.

Quotes delayed at least 15 minutes. Market data provided by Interactive Data. ETF and Mutual Fund data provided by Morningstar, Inc. Dow Jones Terms & Conditions: http://www.djindexes.com/mdsidx/html/tandc/indexestandcs.html. S&P Index data is the property of Chicago Mercantile Exchange Inc. and its licensors. All rights reserved. Terms & Conditions. Powered and implemented by Interactive Data Managed Solutions