Last Friday Wal-Mart shuttered its first unionized North American store, in Jonquière, Quebec.

Meanwhile, a federal grand jury is investigating a former top executive who claims that Wal-Mart made secret payments to union organizers for information about Wal-Mart workers’ union sympathies (if true, a serious offense under the Taft-Hartley Act). Former vice chairman Tom Coughlin, who was number two in the company’s hierarchy before his recent resignation, created fake invoices to get reimbursed for almost conspicuously silly personal expenses, including a $1,359 pair of custom-made alligator boots (bet you can’t find those at Wal-Mart!) and a $2,590 dog pen for his home, according to the Wall Street Journal. The fake invoices, Coughlin has claimed, were simply the indirect way that Wal-Mart agreed to compensate him for the “union project.” Wal-Mart has emphatically denied this.

Some Wall Street analysts think all this bad press, and the ongoing offensive by the unions, may even be depressing Wal-Mart’s stock value. Wal-Mart’s stock price, over the past year, has fallen 19 percent. During that time, the uncelebrated Sears has seen its stock go up. On Wall Street, Target has also been kicking the Bentonville behemoth’s sizable butt.

The unions, for their part, are stepping up their campaign. Last week, the United Food and Commercial Workers kicked off a “Love Mom, Not Wal-Mart” campaign. The retailer is the target of Dukes v. Wal-Mart Stores, the largest civil rights class-action suit in history, representing 1.6 million women and charging Wal-Mart with sex discrimination. Click here to sign the “Mother of all Mother’s Day cards, calling on CEO Lee Scott to put a stop to discrimination . The site also highlights an “Adopt-a-Wal-Mart” campaign, where you can enter your ZIP code to find out about your local Wal-Mart battles.