A topic in the news lately is the upcoming midterm elections. Could they not threaten him with an aggressive informational warfare type of campaign? After all, he benefitted from the coordinated influence campaign that russia undertook during the 2016 elections.
Apple and Googles revenue combine to around 3% of US GDP (substantial!), but it’s not like they would threaten to take that elsewhere or stop selling in the US or something. The ways they can “hurt” Trump hurt them and the rest of the country also. But Trump can do targeted damage to them across many avenues with a stroke of the pen (or even a Tweet)