I would suggest you to ask to Gideon either you can remove powered by or not.
Did none of these come up when you asked the question?
http://www.question2answer.org/qa/6602/how-do-you-remove-the-powered-by
http://www.question2answer.org/qa/705/how-can-we-edit-powered-by-question2answer
http://www.question2answer.org/qa/2281/can-i-edit-the-footer-if-so-where-can-i-find-the-file
Try to edit qa-include/qa-theme-base.php and then find this line '<DIV CLASS="qa-attribution">', 'Powered by <A HREF="http://www.question2answer.org/">Question2Answer</A>', Change it as you want. But i request to keep it if you are using free version. :)
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