You can @ the President of the United States on Twitter

And immediately light yourself up for attention from a hivemind and the utterly unpredictable torrent of entropy that may follow.

Honestly, writing an email probably also gets you there. If sent from the right domain (big bank, asset manager or even pension fund), you'll get attention quickly. It's not about the channel, it's about signaling who's on the other end of the line.

If you IB a CEO with a Bloomberg account from some university or so, you'll probably have little success getting a reply either.