Notice, for example, the terms for changes to their terms of service:
We also reserve the right to modify these Terms of Service from time to time without notice. You are responsible for regularly reviewing these Terms of Service so that you will be apprised of any changes.
(Emphasis mine.) Notice that they do not say that they will notify you when the Terms of Service change. It is your responsibilty to check the Terms of Service. So tomorrow, they could quietly amend their Terms of Service to read, "By agreeing to these Terms of Service, you also agree to pay orkut.com a fee of $50 per day in perpetuity, and you grant that orkut.com or its agents are authorized to use physical force or threats of force to compel such payment," and it is your responsibility to notice this.
And even if you do manage to notice this, their termination clause says
Once your membership terminates, you will have no right to use the orkut.com service. Our proprietary rights, disclaimer of warranties, indemnities, limitations of liability and miscellaneous provisions shall survive any termination of your membership.
Suppose you alertly notice that they changed their Terms of Service and you quickly contact them to cancel your membership. Does that relieve you of your $50/day habit? Nope. The $50/day fee survives termination of the membership. Even though you lose your right to the benefits of membership, they retain the rights to exploit your membership (that you don't have any more but are still paying for).
Of course, any interpretation of the above paragraph is meaningless since they can totally write their Terms of Service at any time and hold you to the rewritten version.
And now vast-left-wing-conspiracy.com can sell your name to hate groups and you can't do anything about it.