Do spammers take the 4th off?

Symantec circulated a message to the press that it stopped some 3.5 million spams over the 4th of July weekend that were using the holiday as a lure. 3.5 million seemed like quite a bit, so I inquired: Is this the largest Spam haul they've had for a holiday?

According their spokesperson, they don't officially track by holiday, but that 3.5 million is actually lower than some previous holiday-related Spam loads. Christmas, the granddaddy of commercial holidays, generates the most Spam.

Why go after the 4th of July though at all? I would think most people are offline and not looking at e-mail, making the spam attack much less effective. Will be interesting to see what Labor Day brings, but no need to rush the summer.