LEADING THE DAY: State Department spokesman P.J. Crowley stepped down Sunday after criticizing the government’s detainment of Pfc. Bradley Manning, who is being held for supposedly leaking documents to WikiLeaks. Crowley clashed with the White House after telling reporters that Manning’s treatment by the government was “ridiculous, counterproductive and stupid.” Manning, who has been detained at Quantico since July, was recently forced to sleep without clothing in the brig after making a sarcastic comment about his confinement. President Obama said Sunday that he has been assured by the Pentagon that Manning’s treatment is “appropriate.”

In other WikiLeaks news, a judge ruled Friday that Twitter must hand over account information from three activists associated with the Web site over objections that doing so would violate the First Amendment.

AT&T to cap Internet use: AT&T announced that it will impose a limit on DSL data usage on its customers and start charging those who exceed that limit. The cap, which will go into effect May 2, will be 150 GB per month for DSL customers and 250 GB per month for the company’s U-Verse customers. According to Dow Jones, those who exceed the limit more than three times in one month will be charged $10 for every 50GB over the limit.

The company will send customers alerts when they approach 65 percent, 90 percent and 100 percent of their monthly allowance.

Facebook, Zynga lend support to Japan: Zynga and Facebook have teamed up with the Save the Children charity to help those affected by the natural disasters in Japan. Players of Zynga’s CityVille, FarmVille, FrontierVille and other titles will be able to donate to the charity through the purchase of virtual goods in the applications.

Many took to Facebook and Twitter to check on the status of loved ones, as Japan’s Internet fared fare better than its cellphone network in the aftermath of the quake. Facebook’s Global Disaster Relief page has an fascinating photo album showing how news of the earthquake and tsunami spread over its network through status messages.

Sen. Al Franken to talk open Net at SXSW: Sen. Al Franken (D-Minn.) will give a speech on the importance of an open Internet to the crowds at the South by Southwest Festival in Austin on Monday. Franken, a vocal supporter of net neutrality, will start the day’s events with his speech, “Open Internet: An Independent Producer’s Last, Best Hope.”

Apple sells out the iPad 2, screen problems emerge: Apple is wrapping up its launch weekend of the iPad 2 tablet, having reportedly sold out of its entire stock. According to analysis from Piper Jaffray, 70 percent of those who bought the tablet were first-time iPad buyers, says Fortune. There are some reports emerging about screen problems with the iPad 2 similar to those reported about Apple’s iPhone 4. The iPhone 4 issues were attributed to a screen-bonding agent in the phone that was not yet dry. According to CNET, some iPad 2 users are reporting similar light leak and screen discoloration issues.