Phishing scams can also occur through email or letter indicating in some fashion that you have won a lottery. The letter/email indicates that you have won this lottery, usually from some foreign country and all you have to do is either send them a "nominal" fee to cover taxes and they will forward the money. Other times they will send you a cashier's check for you to cash with a request to send them back a portion to cover these taxes/handling fees. These checks are counterfeit and like the letters/emails, will most likely contain grammatical errors.
The passing of these checks is considered a forgery. You will put yourself in a position of proving that you are not a willing participant in this fraud. The authors of this fraud are often overseas and are counting on the greed of the recipients to try and cash these checks. Due to the large number of their correspondents worldwide, the amount of money these criminals receive via successful transactions and "taxes/fees" runs into the millions of dollars each year. Remember, if it is too good to be true, it is!
Nigerian letters/emails will represent themselves as successful individuals who are unable to remove their own money from their accounts due to the hostile government where they live, or some other sympathy style story. They request that you do something for them in exchange for money to be sent to you. It may be to set up an American Bank Account or to provide your own account number or it may be to pick up packages for them. If an American responds to them, they will begin to try and convince them to wire money, often thousands of dollars in order to initiate the money transfer. Of course, the victim will never receive any money. If you have received any of these inquiries, ignore them as they are a fraud. Remember, if it is too good to be true, it is!