MODIFICATION OF TERMS
Bitstamp reserves the right to change, add or remove portions of these Terms, at any time, in an exercise of its sole discretion. You will be notified of any changes in advance through your Account. Upon such notification, it is your responsibility to review the amended Terms. Your continued use of the Site following the posting of a notice of changes to the Terms signifies that you accept and agree to the changes, and that all subsequent transactions by you will be subject to the amended Terms.
Highlighting by me, see
https://en.bitstamp.net/article/bitstamp-new-verification-requirements/ as well as the notification in your account.
If you fail to look into your account for weeks and then don't want to supply KYC info, just ask the "Gigamining" people how much it helps to complain.