The use of the pound sign in IRC inspired Chris Messina to propose a similar system to be used on Twitter to tag topics of interest on the microblogging network. He posted the first hashtag on Twitter. Messina's suggestion to use the hashtag was not adopted by Twitter, but the practice took off after hashtags were widely used in tweets relating to the 2007 San Diego forest fires in Southern California. According to Messina, he suggested use of the hashtag to make it easy for "lay" users to search for content and find specific relevant updates; they were for people who do not have the technological knowledge to navigate the site. Therefore, the hashtag "was created organically by Twitter users as a way to categorize messages." Today they are for anyone, either with or without technical knowledge, to easily impose enough annotation to be useful without needing a more formal system or adhering to many technical details.