I need help understanding why does US legal system affords journalistic protection of free speech to credit rating agencies (CRA), especially those which rated mortgage backed securities (MBS) and were heavily involved in the global financial crisis of 2008. I could buy that story if CRAs were publishing their unsolicited opinions on their web-site. But what CRA actually did regarding rating of MBS was solicited and paid expertize that did not only express opinion of future performance of the product, but also actively participate in the design of the product (example, see Levin report p. 287)
On another occasion in March 2007, a Moody’s analyst emailed a colleague about problems she was having with someone at Deutsche Bank after Moody’s suggested adjustments to the deal: “[The Deutsche Bank investment banker] is pushing back dearly saying that the deal has been marketed already and that we came back ‘too late’ with this discovery .… She claims it’s hard for them to change the structure at this point.
That is not what journalists do but more akin to, let say, if I hire a civil engineering firm to design me a bridge. Construction firm observes the project to the letter and builds me one. But the design is so bad that bridge collapses with the very first wind. Why can’t they say - hey, it was only our 1st Amendment protected opinion that the bridge can hold its own weight and function as a traffic infrastructure, holding us responsible if it didn’t would be a denial of the freedom of speech.
On the other hand, CRAs did just that. They inspected the product and gave it highest rating available. Investors would pour money and security would fail a few months later, but it seems that CRAs hold court tested immunity for whatever they say. It should also be noted that these securities were failing for intrinsic reasons - simply , teaser rates ran out for underline obligations or they were unable to refinance or documentation was so lacking that proper assessment could not be made, but that can not exonerate CRAs as all those information was available at the time of rating.
So what is the key legal difference that distinguishes CRA and all other professionals that are actually responsible for their work?
 Wall Street and Financial Crisis: Anatomy of a Financial Crisis, US Senat PSI