Obama's new personal Twitter account

President Barack Obama made his first post from a new personal Twitter account Monday morning, and later reached 1 million followers faster than any account in history.

Within 25 minutes of the post, the president's new account—@POTUS—had more than 103,000 followers. ( Tweet This)

In fewer than 6 hours after that tweet, Obama had amassed more than a million followers.

Prior to Monday, actor Robert Downey Jr. had reached 1 million followers faster than anyone else after an initial tweet. He managed that feat in about 23 hours last year.

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This is not Obama's first tweet: The president used to tweet from @BarackObama, but that was taken over by grassroots group Organizing for Action when he took office. Since assuming the presidency, he has occasionally tweeted from that account and @WhiteHouse—signing his tweets "-BO."

Here are some of the responses from political colleagues, CNBC staff and others to Obama's new social media profile: