It's that time of year already: even though you're still stockpiling your Halloween candy and figuring out whether to be a pirate or a ninja, retailers are gearing up for the holiday shopping season. That shopping season officially begins, of course, with the day after Thanksgiving, known as "Black Friday" in the US. But unlike previous years, some retailers aren't waiting until after the bargain sites post their leaked Black Friday ads in order to threaten them with legal action. In Wal-Mart's case, it's making a few preemptive strikes in hopes of preventing its prices from being leaked too early.

"It has recently come to our attention that you and/or your company may potentially obtain possession of and ultimately release Wal-Mart's sales circulars, advertisements or other information prior to their authorized release dates," reads the letter sent to several deal sites and posted by Chilling Effects. "Please be advised that the information on Wal-Mart's circulars and advertisements are, prior to their authorized release date of November 19, 2007, confidential and proprietary information of Wal-Mart. The circulars and advertisements, as well as related documents are also protected by copyright and other laws. Therefore, any unauthorized reproduction, publication, or distribution of the information or materials (e.g., via website) prior to Wal-Mart's authorized release date violates Wal-Mart's rights."

Wal-Mart warns that anyone who violates the company's terms by posting the Black Friday ads before the specified date could be subject to "liabilities and severe legal penalties," and that the documents are protected by "copyright and other laws."

This is not the first time that retailers have tried to claim that their sale prices were copyrighted. Best Buy began to make headlines in the last few years for sending DMCA takedown notices to the ISPs of sites that published its prices. It claimed that prices are not facts, but rather intellectual property that can be copyrighted—something that deal site FatWallet disagreed with in 2003 when it sued Best Buy for abuse of the DMCA.

But as Chilling Effects founder Wendy Seltzer points out, it looks like Wal-Mart is attempting a new strategy with its early notices by making broader claims about its "commercially valuable" pricing information. By making these claims, Wal-Mart could be looking to get in under trade secret laws that prohibit the transmission of information that affect the company's sales (other companies may see the prices and decide to alter their own to better compete). Wal-Mart is making sure that the sites know that they could be misappropriating confidential information, which might then allow the company to pursue further legal action in the future if the sites still push forward with the sale prices.