Yahoo Mail surveyed 3100 people in May about spam. One-fifth of the US residents said they have bought products from spammers. Twenty percent! It’s enormously difficult to draw the line between “spam” (a despised scourge) and “advertising” (a legitimate attempt to market a product, even if unsolicited). How can you legislate against the “Vi ag3 ra” ads that are slipping through the spam filters, if people are buying products in response to the messages?