Google Letting Third Parties Read Your GMail
 

According to an article from the Wall Street Journal, one of Google’s many dirty secrets is that it allows application developers to sift through users Gmail addresses. Basically, Google allows third parties to read your email. There’s no other way to describe it. Software developers were allowed by the tech giant to scan/read the emails of hundreds of millions of Gmail users, Google’s proprietary email/communications service.

Complete story here.

Read the comments below the hysterical article pointed to by the OP.
Basically if you give permission for a 3rd party application to access your email, don't be outraged if the said 3rd party reads your emails.