The Trump administration on Tuesday removed Moscow-based Kaspersky Lab from two lists of approved vendors used by government agencies to purchase technology equipment, amid concerns the cyber security firm's products could be used by the Kremlin to gain entry into U.S. networks.

The delisting represents the most concrete action taken against Kaspersky following months of mounting suspicion among intelligence officials and lawmakers that the company may be too closely connected to hostile Russian intelligence agencies accused of cyber attacks on the United States.

U.S. President Donald Trump on Monday signed a repeal of Obama-era broadband privacy rules, the White House said, a victory for internet service providers and a blow to privacy advocates.

Republicans in Congress last week narrowly passed the repeal of the privacy rules with no Democratic support and over the strong objections of privacy advocates. The signing, disclosed in White House statement late on Monday, follows strong criticism of the bill, which is a win for AT&T Inc, Comcast Corp and Verizon Communications Inc. The bill repeals regulations adopted in October by the Federal Communications Commission under the Obama administration.

Donald Trump seems to have finally traded in his old and unsecured Android phone — for a new iPhone.

White House director of social media Dan Scavino Jr. tweeted tonight that Trump had switched to the Apple device, saying that he had been using it for "the past couple of weeks," and confirming that Twitter messages marked as coming from an iPhone were indeed from the president himself. Twitter users noticed that some of Trump's tweets appeared to be sent from an iPhone over the last few weeks, but it wasn't clear whether they were written by his own hand, or by staff members on secondary devices.

Donald Trump's phone use is raising security concerns among a pair of senate Democrats. Sens. Tom Carper and Claire McCaskill sent a letter last week to Secretary of Defense James Mattis about whether the president is using a secure device to make calls and post tweets.

The senators, who both service on the Homeland Security Committee, worry that an unsecured device could be vulnerable to hacking, posing a national security risk. "Public reports originally indicated that President Trump began using a 'secure, encrypted device approved by the U.S. Secret Service' prior to taking office," the senators wrote in the letter, which was made public Monday.

President Trump has carried his Twitter habit into his presidency. He has also brought with him another tech habit that is causing concern. Mr. Trump has been using his old, unsecured Android phone to post on Twitter since moving to Washington late last week.

The president’s use of an unsecured personal device raises concerns that his desire to use his old smartphone could be exposing him and the nation to security threats. He is using the Android smartphone mainly to post on Twitter, not to make calls. But it’s unclear what security measures have been put in place on the device and how vulnerable he could be to someone stealing data or breaking into his Twitter account.

A few hours after President-elect Donald Trump was briefed by intelligence officials about Russian meddling in the election, a reporter called his cellphone seeking an interview. The call went to voicemail and the reporter did not leave a message. About an hour later, Trump called back.

It's hard to imagine many politicians — particularly one about to become president of the United States — calling back an unknown number on their cellphone. With Trump, it's simply how business gets done, whether he's fielding calls from real estate partners and longtime friends or foreign leaders and congressional lawmakers in the weeks after the election.