Activist investor Bill Ackman has decided to get a little more active online. The Pershing Square Capital Management chief executive officer joined Twitter Thursday under the handle @BillAckman1.

Ackman, known for public campaigns against companies including nutrition company Herbalife Ltd. and Air Products & Chemicals Inc., hadn’t sent a tweet as of 2 p.m. The account also lacks a photo, which is one of the usual requirements to get an account officially verified on Twitter Inc.’s social media platform.

Ackman confirmed he owns the account in an email.

The account is currently following 46 others, including President Donald Trump, News Corp. founder Rupert Murdoch, Amazon.com Inc. CEO Jeff Bezos, Tesla Inc.’s Elon Musk, and Goldman Sachs Group Inc. CEO Lloyd Blankfein, who is new to the service himself. Ackman also follows an unverified account featuring poker-related tweets that’s widely believed to belong to Greenlight Capital Inc.’s founder David Einhorn.

Outside of the business world, Ackman also follows the accounts of "Hamilton" creator Lin-Manuel Miranda, up-and-coming tennis star Frances Tiafoe, and the account @Queen_Europe -- a parody account of German Chancellor Angela Merkel.

The account doesn’t follow fellow billionaire activist Carl Icahn, with whom Ackman has had notable public run-ins in the past over their respective bets on Herbalife.

Hedge fund Pershing Square typically buys stakes in a handful of big companies and agitates for executives and directors to make changes to boost shareholder returns.

Ackman in March “deeply and profoundly” apologized for his investment in Valeant Pharmaceuticals International Inc., a “huge mistake” that cost his firm $4 billion.