Three different people asked me yesterday about why two buddies known as 'bots' showed up in their AOL Instant Messenger Buddy List. The new buddies were called "Shopping Buddy" and "Moviefone". One of the people had been given a message when they logged in mentining that these new buddies were added, but the other two people did not receive any such message.

In the context of instant messaging, a 'bot' is a computer program designed to respond to messages as if it were a person. It can interpret questions and statements made in natural language and send some sort of (hopefully) appropriate response back. Companies and individuals have developed bots for any number of purposes.

There have been infomation bots, like "SmarterChild", that give you movie showtimes and horoscopes, and play simple games. There are advertising bots that dispense product information, and there are attack-bots that inundate a user with so many messages that it causes their account to shut down.

AOL's new bots are designed to act as a shopping search engine and provide movie times.

Many bloggers are up in arms about the fact that AOL automatically added these new bots to every user's buddy list rather than giving individuals the choice of whether or not to install them in the first place. It's a fairly minor inconvenience to remove them from your list, but critics compare AOL's approach to 'opt-out' spamming.

An 'opt-in' list is one where you have to do something specific and clear, like submit your e-mail address in a form, to start receiving the list's mail. An 'opt-out' list is where the list assumes you want to receive its mail until you do something specific and clear to unsubscribe yourself. Although the CAN-SPAM act considers opt-out lists acceptable (provided the opt-out works within 10 days), many spamwatchers consider this practice highly undesirable for end-users. In my opinion, best practices dictate using opt-in lists only.