Trump Bans TikTok September 20

This is some passage in article.

“The legal powers behind the executive order is unclear. [... Typically sanctions] are put in place by the Commerce Department, rather than the White House, and subject to a rule-making procedure that seems to have been short circuited by the surprise executives order.”

Was this necessary? If it was really a national security threat he would have made the ban effective much sooner. Now it just looks like it’s part of a shakedown to give Microsoft or some other interested party more leverage.

This feels like a fairly scary precedent. It also sounds fairly non specific - what counts as a "transaction"?