ISX are well within their own rights to request reasonings as to...

ISX are well within their own rights to request reasonings as to why certain bits of information is required (For example; Shareholder identities). You have to remember the ASX are not a regulatory body. They have no power to prosecute. Information that they request must only be material to the listing of the companies SP. Any information being requested outside of this, is clearly phishing for information and over reach.

Now the ASX might not need to respond to any of ISX requests but they are still a publicly owned entity and as such, bound by the rules of the Corporations Act, which is a two way street in a court of law. Any act's of over-reaching can seriously impact on their own reputation as a Tier 1 stock exchange and negatively impact on it's own shareholder interests.