https://www.theverge.com/2018/3/31/17184000/president-donald-trump-amazon-usps-washington-post-tweets

This morning, Trump once again tweeted about online retailer Amazon.com, alleging that it is scamming the United States Postal Service and that the agency should raise its shipping rates. He also says that The Washington Post — owned by Amazon CEO Jeff Bezos — should register as a lobbyist.

Earlier this week, Axios reported that President Donald Trump wanted to take on Amazon. The President followed up with a tweet on March 29th, saying that Amazon was taking advantage of the USPS, paying little in state and local taxes, and putting retailers out of business.