TLDR:

Pinterest is getting lots of criticism from press on specific issues and they are editing them.

* "pro-ana" (anorexia) pinboards containing "thinspo" (pictures and sayings to reinforce anorexia) were featured in a Jezebel post. Pinterest clamped down and said they won't tolerate self-harm. See:

http://jezebel.com/5893382/the-scary-weird-world-of-pinteres...

* You need copyright permission to post something to Pinterest but virtually nobody has permission, so they added better takedown methods. See:

http://www.npr.org/2012/03/22/149169388/pinterest-wades-in-m...

* Pinterest is adding private pinboards and an API.