Whilst you can't compel foreign software developers not to talk about what they've been asked to do, there are probably a couple of ways this remains possible:

Whilst you can't compel foreign software developers not to talk about what they've been asked to do, there are probably a couple of ways this remains possible: (a) Disclosure would likely result in liability for the executive officers and/or Company Directors, which might be contempt of court, or something more serious; (b) Software developers working for Apple (an example) are likely under strict Non-Disclosure Agreements as part of their employment contracts, so the company served with such a request will likely make it clear to those responsible for technical implementation that it's covered by NDA. Even in the case of (b) if a developer quits rather than implement the functionality, in many jurisdictions, the employer would have grounds to pursue a gag order.