There is no a reliable way to know that. A Web site can have a legal registration, but how can you know it does not do any illegal activity?
Perhaps, the only thing you can do is using HTTPS pages and checking its
digital certificate signed by a well-known
certificate authority. See:
http://en.wikipedia.org/wiki/Public_key_certificate[
^],
http://en.wikipedia.org/wiki/Certificate_authority[
^].
However, you should understand: this only ensures that the Web page is not fake in the following sense: it belongs to the company mentioned in the certificate, so it is not a third party trying to impersonate as some other organization. This has no legal implication about the content and behavior of the Web page itself; it says nothing about legal or illegal activity associated with this Web page.
Come to think about, just ensuring of the validity of the identity of some organization is already a great step to safety.
—SA
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