In Mexico, as though other crime problems weren't enough, there has been a recent spate of lottery scams, usually conducted by phone, telling people that they have won a prize or lottery, and should stop by a specific address to redeem their claim and submit some paperwork.
What makes this different from the usual Internet Advance Fee Fraud is that usually people in a specific city are targeted, and they are asked to visit a specific office, which means that the victim comes into face to face contact with the scammer. Otherwise, it's straightforward Advance Fee Fraud: the victim is invited to complete some forms, provide some identification and other information, and invariably, to pay a processing fee. He or she is then told that the claim has been entered and the prize can be redeemed in a few days, will be credited to a bank account, or that he or she will be notified by phone once the funds are ready, or some such. Of course it never happens.
In Mexico office space can be rented for a day or for a similar short period, so basically the scammers try to make a large number of people show up and pay them within a short time frame, and then proceed to disappear. Invariably, the person or company who rented out the office on that particular occasion is found not to exist, and any other contact details used in the scam or provided for the rental are temporary, fake, or both.
The best way to keep from falling victim to this scam is to remember one basic thing: you can't win a lottery that you haven't entered.