Walmart sells just about everything-from groceries to garage doors to guns. But, they don't sell fighter jets (at least, not yet). So, why would they need to contract with the defense contractor, Lockheed Martin?

Turns out that Lockheed Martin, has a division that does intelligence gathering, and Walmart hired them to gather data on pro-union employees and activists. Walmart has made no secret that they oppose the unionization of their employees. Union activists have been trying to unionize Walmart's workforce with little success. But, is Walmart's strategy of hiring a company to spy on people a good one?

Walmart is facing a hearing in front of the National Labor Relations Board (NLRB), and as such isn't commenting other than to say, via an email to Bloomberg Businessweek:

We are firmly committed to the safety and security of our 2.2 million associates as well as the 260 million customers we serve each week. It's important to remember that Walmart is the largest company in the world with 11,500 stores in 28 countries. Unfortunately, there are occasions when outside groups attempt to deliberately disrupt our business and on behalf of our customers and associates we take action accordingly.

The NLRB is very pro-union and recently changed the rules on union elections to speed up the process, which will most likely be a help to unions. Walmart is understandably worried.

Should you spy on your employees if you suspect they are leaning towards unionization? Most companies can't afford to hire a defense contractor to spy on employees, and depending on how the NLRB rules on the Walmart case, may or may not be illegal.

Spying is legally sketchy at best, and I wouldn't recommend going down that path unless you have an army of lawyers that can carefully craft a plan. What should you do instead? Employment attorney Jon Hyman suggests a TEAM approach to preventing unionization at your workplace. TEAM stands for:

Train supervisors

Educate employees

Affirm the open door

Modernize policies

Train your supervisors on how to act and respond if they hear any talk of unionization. Remember, this can be a legally tricky situation, so proper training is a must.

Educate your employees on why it's best to keep unions out of your company. For instance, Hyman suggests pointing out that you've had a peaceful history of discussions between management and employees, and that it's unnecessary to have a third party intervening.

Affirm the open door means management needs to be constantly listening and responding to what they hear. If employees are punished when they bring up problems, they will go around the management instead of working with the management.

Modernize your policies. Think everything is the same today as it was last year? The new union election policies have only been in effect for six months. Do you think they will be the same in another six months? Maybe, maybe not. You should have at least an annual review policy so that everything is up to date. Double check with your employment attorney.

If you want to build a culture of distrust, spy on your employees, refuse to hear feedback, and speak negatively about unions. The result could be a unionization that you don't want. Be pro-active and above board, and keep your eye on this spot for how the spying case comes out.