The White House has been caught writing many of Trump's tweets for him, as his staff intentionally puts typos and grammatical errors in his tweets to make them look authentic.
Reckless Trump Violated The Law For Days Before Finally Securing Twitter Account
The President's Twitter account that can allegedly drive the markets, cause boycotts by endorsing a product, and incite international issues was reportedly secured with a private email. That is to say, not very secure. Easily hacked.