is wrong. It currently states:
“App.net reserves the right to change or modify any of the terms and conditions contained in the Site Terms or any policy or guideline of the Sites, at any time and in its sole discretion. Any changes or modification will be effective immediately upon posting of the revisions on the Sites, and you waive any right you may have to receive specific notice of such changes or modifications. Your continued use of the Sites following the posting of changes or modifications will confirm your acceptance of such changes or modifications.”
This is not true. The current terms state:
We reserve the right to modify these Terms at any time. For instance, we may need to change these Terms if we come out with a new feature or for some other reason.
Whenever we make changes to these Terms, the changes are effective 5 days after we post such revised Terms to our website (indicated by revising the date at the top of these Terms), or when we notify you of the changes by e-mail or other means, or upon your acceptance if we provide a mechanism for your immediate acceptance of the revised Terms (such as a click-through confirmation or acceptance button). It is your responsibility to check the website regularly for changes to these Terms.
If you continue to use the Service after the revised Terms go into effect, then you have accepted the changes to these Terms.
So it's 5 days after posting, and in some cases you will be notified. You also agree that it's your responsibility to stay up to date. As there is https://github.com/appdotnet/terms-of-service
I think there are plenty of resources for users to do so, so I would change this from mediocre to notice (at least).