Hunton & Williams, the law firm that solicited HBGary and two other security firms to spy on Chamber of Commerce opponents, has remained silent so far about its efforts.

But it hasn’t covered its tracks. The SEIU reports that people from Hunton & Williams spent 20 hours last November–at the time when Themis was pitching H&W to use a JSOC approach to go after Chamber opponents–on the SEIU sites.

Server logs and leaked emails reveal that employees at Hunton & Williams, the principal law firm of the U.S. Chamber of Commerce, spent 20 hours on SEIU websites last November while partners from the firm were working with private security firms on an illegal “dirty tricks” campaign aimed at undermining the credibility of the Chamber’s political opponents, including the Service Employees International Union (SEIU).

And of course SEIU is able to see precisely what H&W was looking at in that period: top H&W page views in 2010 include SEIU’s page on the Chamber and on big banks. People from H&W searched on individuals at SEIU as well as on SEIU’s organizing of protests outside of BoA’s General Counsel. They even searched on “hourly pay for SEIU organizers.” (Whatever that is, it’s less than Themis was going to charge for its paid trolls.)

No wonder H&W has been so quiet about their role in this campaign.

Update: This post has been edited for accuracy.