From a Twitter How-To, Another Lesson It was in the wee hours of Thursday when Bill Costello, known as @BC on Twitter, realized that something unusual was happening. His phone kept vibrating, notifying him of activity on his Twitter account. "I happened to look at it once, and it said something like 40 new interactions," he said. I was like, wow, something is different. A few hours earlier, an article I wrote about using Twitter was published. Turns out, Mr. Costello's experience helps show how Twitter works. The headline for the article included "@BC," which is coincidentally Mr. Costello's Twitter account name, or handle. Twitter users have the option of being notified whenever their handle is mentioned in a post. Each time a reader tweeted the article with the headline, "Twitter Illiterate? Mastering the @BC's," Mr. Costello received automated notifications that he had been mentioned by someone on Twitter. For Mr. Costello, that meant he was flooded by more than a thousand mentions on Thursday. Mr. Costello, a software developer in DeLand, Fla., said that it was not unusual for him to receive occasional mentions that were not intended for him. Every so often, people meaning to refer to Boston College, for example, mention him instead of @BostonCollege. It's never bothered him in the past, he said. And when people have offered to pay Mr. Costello, who joined Twitter around 2007, for his two-letter handle, he has always turned them down. Luckily, Mr. Costello took it well. He wrote this to me on Thursday morning: Once he realized that he was in the spotlight, he checked his Twitter page including his bio to make sure it did not say anything inappropriate. He then went through many of the messages, looking at people's bios to see who they were and where they were from. He found it interesting, he said, to see such a wide range of people sharing the article. Some of the tweets were written in foreign languages. "That's one of the things that appeals to me about Twitter," Mr. Costello said. I don't have to surround myself with a circle of people just like me. There are all kinds on the planet and hanging out on Twitter. The incident had the other unintended consequence of leading to some new Twitter friends - or at least new followers - for Mr. Costello. He responded to those who realized the headline included his handle, thanking them for noticing and chatting with them. He followed those he found interesting. Some followed him back. "I think it worked out just fine," he said.