Domain Registry of America
Every few weeks, we'll have a customer present us with a "bill" from a company called Domain Registry of America. These "bills" aren't really bills, because they are specifically sent to people who aren't customers! It's an attempt to get customers to transfer their domain name to DRA. The problem is that they're deceptive in that effort.
Register.com got an injunction against DRA in 2002. The judge in that case noted that the principals of the company had previously been convicted of other unlawful activities and noted that their tactics were "neither accidental nor innocuous, but calculated and intended to confuse and mislead consumers."
There is even a name for this sort of practice - domain slamming, much like the practice of phone companies switching you to their service without the consumer even understanding what they've agreed to.
There is a picture of their fake "bills" here. If you get one, the best thing you can do is throw it away!