President-elect Donald Trump has pledged to stop TikTok going dark—but tech companies who help him risk incurring $850 billion in fines.

Apple Inc. and Google removed TikTok from their mobile app stores in the US as required by a law that took effect Sunday, after the social media company’s legal challenges failed to head off the measure passed last year to address national security concerns.

With President-elect Trump adding uncertainty around whether a TikTok ban will go into effect, the focus is now turning to companies like Google and Apple.