From the NaNoWriMo TOS:
The Office of Letters and Light reserves the right to change the terms and conditions hereof without prior notice at any time and any such change shall be effective immediately upon posting the changed Agreement on NaNoWriMo.org. The effective date indicated at the top of this page will be updated to indicate that changes have been made. You should, as a condition of continuing to access NaNoWriMo.org and use its features, periodically review the terms of this Agreement and such continued access and/or use shall be deemed to be conclusive evidence of your agreement to be bound by any such changed Agreement.
No, I will not write the Office of Letter and Light a blank check.