Tumblr can do whatever they want with their site, this includes changing it by enabling or disabling the availability of features or content.
Tumblr can impose limits on your account, and keep you from accessing something on the site.
Tumblr can change the TOS at anytime, but they have to let you know about it.
You have to be at least 18 to use Tumblr.
Tumblr is not responsible is you can’t use it outside of the US.
If Tumblr is not responsible for it’s own unavailability, well, it may be, but you can’t hold them liable if your content is unavailable due to their downtime.
It’s not Tumblr’s fault if you decide to use IE6 and the site looks like shit, you need a better browser.
Everything on the site, except for content posted by the users, belongs to Tumblr.
You can’t copy or modify anything that belongs to Tumblr without their permission unless it’s for personal use.
If use Tumblr to post content, Tumblr do stuff with your content.
You can’t post content that infringes or otherwise interferes with any copyright or trademark that is not your own.
You can’t use Tumblr to reveal any trade secrets
Your content can’t be is libelous, defamatory, obscene, pornographic, abusive, indecent, threatening, harassing, hateful, offensive or otherwise violates any law or right of any third party.
Don’t post anything that will hurt anyone’s computer
Tumblr can delete any of your content or even your blog.
Don’t do anything illegal with Tumblr. This includes Cyber Crime.
Tumblr cannot and will not control who sees what on the site.
The content on the site, submitted by users, is in no way related to Tumblr, Inc.
If Tumblr FAILS and your content is lost, it’s not their fault.
If something on the site doesn’t work, they will fix it, but legally it’s not their fault.
It’s not Tumblr’s fault if you get a virus from a tumblelog.
Tumblr has no control over anything that happens with you click a link on Tumblr that takes you to another site not on Tumblr.
You need a username and password with Tumblr.
You need to make sure Tumblr has a working email address for you
You can’t pretend to be someone else on Tumblr.
You need to tell Tumblr is someone finds your password.
You can’t hold Marco liable if something is broken.
If Tumblr decides to charge for it’s service, they have to let you know 10 days in advance.
Tumblr can terminate your account or you can terminate your account at any time.