What's to keep the US government from fining companies or suspending their ability to do business until they give up user data? For example, London suspending U

What's to keep the US government from fining companies or suspending their ability to do business until they give up user data? For example, London suspending Uber's ability to operate in the city. While I'd agree that small-ish foreign companies can probably fly under the radar, I don't think any company that receives payments from US customers is immune to coercion from the US. If the US government can impede a company's ability to access US customers then that's an ability to compel a company to give up data.