I used to post links to the debunking articles about this, but I've seen so many questions about this absurd "Yahoo / Internet Lottery" that I don't bother anymore. The people posting clearly can't be bothered to type two words into a search engine, or read the links Yahoo brings up when you try to submit a question about it.
My favorite so far is a chump who posted, claiming to have fallen for the Yahoo Lottery scam.
Please suggest and help me from MSN yahoo. lottery!?
I've sent all of my documents, address, ID, bank information, swift code, even bank initial to the said Yahoo.MSN Lottery authority. Do they disburse any amount without my permission?
He is now the victim of identity theft. His information will likely be used for a variety of illegal purposes. Credit cards will be opened in his name, his existing accounts are compromised. Institutions where the scamers think he may have accounts may be contacted by people claiming to be him so as to clean out those accounts as well.
his name will probably end up on forged ID cards, resulting in his name being used by illegal immigrants and criminals. He'll probably end up with a criminal record under his name, and some folks may even be convicted of felonies under his name. I saw a news report not to long ago about a guy who had to give a copy of a letter from the government to new employers, explaining how the Felony conviction under his name and Social Security Number is NOT him, but an identity thief who'd been using his name, even serving jail time under the stolen identity, for YEARS.
He's screwed, all because he didn't do a little bit of research before blindly believing an e-mail that was too good to be true.
Naturally, Yahoo has addressed this question on their own site. Their Help Section has a entry entitled: Is there a Yahoo! Lottery? Does Yahoo! Mail ever offer cash prizes?
The short version of their answer is: No such lottery exists.
It's a scam folks, and people keep falling for it despite the fact that it can be debunked with 30 seconds of research.