I know if on my own webpage, if my user is on :
http://www.example.com/form.php
and I make an ajax request from that page to : http://example.com/responder.php
There are few known methods to work around the Same Origin Policy. One popular technique is to use "Script Tag Injection" such as in JSONP. Since the <script>
tag is not constrained by the Same Origin Policy, a script on a third-party domain can provide executable code that interacts with a provided callback function. You may want to check out the "Tips and Tricks" section in the following article for further reading on the topic:
You may also be interested in checking out the following Stack Overflow post for further reading on other techniques to work around the Same Origin Policy:
UPDATE: Further the updated question:
Quoting from the jQuery documentation on $.getJSON():
If the URL includes the string "callback=?" in the URL, the request is treated as JSONP instead.