A similar package was discovered at the offices of the Williamson County Republican Party last Friday.
Meanwhile, over the last few days on Pastebin.com, a website popular with hackers, a pair of posts have been circulating, one with language similar or indentical to that found in the envelopes at the county party offices. The posts, whose authors are unknown, say that Romney tax documents were stolen several days ago from a PricewaterhouseCoopers' office in Franklin.
"Romney's 1040 tax returns were taken from the PWC office 8/25/2012 by gaining access to the third floor via a gentleman working on the 3rd floor of the building," one post reads. "A package was sent to the PWC on suite 260 with a flash drive containing a copy of the 1040 files, plus copies were sent to the Democratic office in the county and copies were sent to the GOP office in the county at the beginning of the week also containing flash drives with copies of Romney's tax returns before 2010."
A second post says that encrypted copies of the tax documents will be sent to major media outlets, and demands the equivalent of $1 million in Bitcoins, a virtual currency, in exchange for a purge of "the keys to unlock the data." Alternately, the post says that anyone interested in the documents can send the same amount of money in exchange for the release of the encryption keys.
"Failure to do this before September 28, the entire world will be allowed to view the documents with a publicly released key to unlock everything," the post reads.
On Wednesday, PricewaterhouseCoopers said in a statement that there was no evidence that anything had been stolen, but the company did acknowledge that it was working with the Secret Service:
We are aware of the allegations that have been made regarding improper access to our systems. We are working closely with the United States Secret Service, and at this time there is no evidence that our systems have been compromised or that there was any unauthorized access to the data in question.
George Ogilvie, a Secret Service spokesman, confirmed to TPM that the agency is "investigating the incident," but could not add further details.
In an interview with The Tennessean, the executive director of the Williamson County Republican Party said she also initially thought to treat the matter as a hoax.
"A million dollars seemed kind of low," Jean Barwick told the paper. "If you're going to go for a million, why not go for $100 million."
At first, she contacted only the state GOP, to see if it got a similar package. But then on Wednesday, Barwick decided to contact the police. Charles Warner, a spokesperson for the Franklin Police Department, told TPM that based on what officers were told, the department called the Secret Service. (Warner added that the Franklin police did not respond to any complaints at the offices of PricewaterhouseCoopers' during August.)
No one from either county party appears to have attempted to look at the contents of the USB drives.
Burr, the Democratic Party Chairman, said he had kept the USB drive in his briefcase. At one point, Burr said, he considered plugging the drive into an old computer, but he said the "last thing I wanted to do was plug it in to a computer that I cared about."
Wednesday morning, Burr's office started to get calls.
"We got a call from an affiliate of The Tennessean newspaper here," Burr said. "Almost immediately after that we got a call from the Secret Service."
Secret Service members came by a few hours later, and took the materials with them.
Additional reporting by Carl Franzen