Castor oil residue found on a letter addressed to Bloomberg.

You will likely read in today's news that letters were sent to Bloomberg that were stained with some yellow oily substance. They were tested by NYPD and revealed traces of ricin. If you read the wiki article on ricin, you will find out that toxic ricin is a powder and not some oil.  You will also learn that castor beans are the source of ricin and that castor oil is a popular remedy for many conditions. It is used in skin care and, even more commonly, as a laxative.

It must be a very potent laxative because even trace amounts on these letters caused Bloomberg and the NYPD to shit their pants.  Bloomers didn't even touch the letter and only heard of it.