Imagine you work for a New Zealand company with an entrenched monopoly. You think your website is pretty good, and you do a lot of business that way. But maybe you want to know what people really think. Perhaps you worry that your customers don't like you as much as they should.

...

So you take action. You decide to post a comment defending your company, but pretending to be from one of your happy customers. No-one will ever know, and it will help even up the balance a bit. Perhaps you even feign illiteracy in your "happy customer". You think your customers are a herd of illiterate sheep after all.

But you forget two important things.

1. You are not completely anonymous when you surf from work.
   
2. You are a complete idiot.

The whole 9 yards here and here.