Bad customer service cuts both ways.

Companies can provoke their customers to do extraordinary things, from angrily confronting their employees to burning down a car dealership.

But sometimes, it doesn’t take much to set a consumer off.

Sometimes, they’re just having a bad day, and when they’re asked to wait or given a routine “no,” they snap.

Anyone who doubts there are bad customers should look no further than the data compiled by the National Retail Security Survey. American retail business, it found, lost $33.5 billion to what’s euphemistically called “shrinkage” last year – losses from shoplifting, internal theft and other types of criminal activity. But the news isn’t all bad: The number is down from $36.5 billion in 2008.

Which is why you need to watch these videos. They’re great examples of how not to behave when you’re a customer.

1. Take back your burger

What happened: Alesha McMullen (above) reportedly didn’t like the hamburger she ordered from a Kansas City McDonald’s last December. They offered to replace the meal. It wasn’t good enough, so she went on a rampage in which she threw a bucket of water over the counter and toppled three cash registers, causing $3,000 in damages. Then she fled. Police later arrested her and charged her with felony damage.

Why it doesn’t work: The “angry customer” routine is counterproductive, especially when combined with property damage. Did McMullen really think that sending a cash register to the ground would result in a refund?

2. Passenger loses it

What happened: A passenger gets angry at an Alitalia ticket agent in Rome. This kind of thing probably happens frequently, but on this particular occasion, another passenger captured the incident on camera. You probably won’t understand the angry tirade in Italian, but you don’t need to speak the language to read the defensive body language of the ticket agents, who will most certainly not help him as a reward for his tantrum.

Why it doesn’t work: Yelling at a customer service agent is just a notch below destroying property. It’s equally effective.

3. That’s not a meltdown — this is

What happened: A Chinese woman missed her flight from Hong Kong to San Francisco, and didn’t take it well. Unlike the man in Rome, who merely was yelling at the ticket agents, this one had to be restrained. (She is yelling, “I want to go! I want to go!” in Cantonese). The Cathay Pacific flight on which she is booked was no longer accepting passengers.

Why doesn’t it work: It doesn’t reflect well on her, but in one sense, it does work. She was reportedly accommodated – at no extra cost – on the next flight to San Francisco.

4. “When was this hotel built, the 40s?”

What happened: I can’t vouch for the authenticity of this video (the audio is too good to come from a surveillance camera) but I’m including it because it summarizes several other customer meltdowns in a succinct, three-minute video. In it, a disgruntled guest beats up on technology, berates the staff and makes demands they’re unable to immediately meet. All perfectly bad form.

Why it doesn’t work: I don’t know how they found Will Ferrell for that video. But it demonstrates that flipping out – whether your disappointment is aimed at power outlets, the employees or cell phone coverage – is utterly useless. It could get you escorted off the property by security, which appears to be how this video ended.

5. Say hello to my little friend

What happened: This police video from Lawrence, Mass., shows a man entering a store, apparently upset over the service. He brandishes a gun and then uses the weapon to smash a counter. There’s no audio, which is normal for surveillance videos. The case appears to still be unsolved.

Why it doesn’t work: Do I really have to tell you? Threatening violence is more likely to get a customer locked up than have his or her grievance addressed.

Bad behavior – whether it’s yelling, throwing yourself on the floor, wielding a gun or just being plain obnoxious – is no way to get the customer service you want. Take a clue from these videos.

Being like this will just get you into trouble. Lots of it.