Conspiracy theories sometimes are true. Yesterday, Yahoo! had to shut down operations for three hours in the middle of the day due to "mock" traffic. What seems to be users to the site is, in reality, a computer hacking through the Internet, making Yahoo! so busy that regular visitors cannot access the site.
The attack came from multiple locations all at the same time, and because of the breadth of activity, the company could not prevent a shut down.
Yahoo! says they do not know who is responsible for the mock traffic, and verified that no user data was lost and security was not violated.
In addition to user woes, the site's shut down also affects business partners, like EBay, who in the past, was severely affected at its bottom line by similar outages. Yahoo! is the second most visited site on the Internet, following AOL at the number one position.