LEADING THE DAY: Twitter co-founder Jack Dorsey will moderate an online discussion with President Obama Wednesday, in what’s being billed as the White House’s first Twitter town hall, The Washington Post reported. Dorsey will cull questions and themes for the president from thousands of inquiries submitted with the hashtag #AskObama.

Obama’s staff and Twitter officials will then send out 140-character responses from the president. About 13 percent of Americans online use Twitter. Twitter users tend to be young, politically engaged professionals, according to a study from the Pew Center.

The Washington Post’s Cecilia Kang and Mark Luckie will be on location and tweeting the event, and Post politics reporter Chris Cillizza will live-blog.

Verizon ending unlimited data plans: Verizon will end its unlimited data plans Thursday, The Washington Post reported, opting instead for tiered plans. Existing customers will not be affected by the change, though Verizon did not say how renewing subscribers will be affected.

AT&T and T-Mobile have also moved away from their unlimited data plans.

“It is a shame that Verizon and the other companies see the need to ration bits of data for their customers,” Gigi Sohn, president of public interest group Public Knowledge, told the Post. “At some point, consumers will realize these new technologies will be worth very little if they can’t or won’t afford to pay for them.”

Morgan Stanley data breach: Morgan Stanley Smith Barney said Tuesday that compact discs containing tax information for 34,000 clients were lost in transit, Bloomberg reported.

Credit.com, the first outlet to report on the breach, said that client names, addresses, account and tax ID numbers as well as some Social Security numbers were lost. The company looked for the discs for two weeks in an “exhaustive search” of its facilities before notifying customers.

“There’s no evidence that there was any criminal intent here, or actual misuse of this information,” Jim Wiggins, a spokesman for Morgan Stanley Smith Barney, said in a phone interview.

Arizona approves AT&T, T-Mobile merger: The Arizona Corporation Commission approved a merger between AT&T and T-Mobile, The Hill reported, concluding without a hearing that the deal would not hurt utility companies’ ability to “provide safe, reasonable and adequate service.”

South Korean cyber attacks were “war drills”: Security software company McAfee Inc. told Reuters that attacks on South Korean government Web sites in July 2009 and March 2011 may have been “war drills” conducted by North Korea.

Dmitri Alperovitch, vice president of threat research for McAfee Labs, said in the report that a technical analysis from the company found that the denial of service attacks that shut down Korean sites could have been Internet reconnaissance missions to test the impact of cyber attacks.