If you have the time, click on through and review the big scary.
The short story is that in theory folks could be able to check all of the assets in a given CDO, or CDO like asset, to make sure that each asset in the various tranche's conforms to some notion of standard, or standard of value. But that way seems to upEnd the apple cart about CDO' offering a transparency, in which the whole is presumed to be safe enough.
Ah yes, what if there were more than a few issues in the shadow banking system, that have yet to be brought out into the light, disinfected, and put back on the road to a healthy banking system.
What if there is more than one EnronIzer willing to game the system for short term profit over long term economic stability and soundness?