[dalke]

"Nothing to back it up"?

You've considered only the single-use nature of the 20 byte attack, without realizing that that can be done over, and over, and over again.

As moxie pointed out elsewhere in these comments, Travis Goodspeed and Dan Kaminksy embedded a eulogy to the Len Sassaman in the blockchain. See http://pastebin.com/raw.php?i=BUB3dygQ .

But no need to read the other comments, since the author wrote "Some folks have exploited that feature/flaw to publish Wikileaks cables." Information about that publication is in the immediately previous article: "That publishing capability was put into use a couple of days ago when someone publish 2.5 MB of Wikileaks cables in the bitcoin blockchain. It cost a bit of money (about $500) to accomplish that, but the information that was published is now going to be public forever."

A search finds someone who wrote "The wikileaks data starts at transaction 5c593b7b71063a01f4128c98e36fb407b00a87454e67b39ad5f8820ebc1b2ad5".

Therefore, I find your claim that there is "nothing to back it up" untenable.