Tweeters have been filing their tweets by topics with hashtags for years. Now, Mark Zuckerberg is thinking of bringing them to his social networking site.The Wall Street Journal reports that Facebook is taking a page from its social networking rival and may add a hashtag feature to its service, which would allow users to search for keywords within the social network.If the report is true, Facebook could start looking a lot more like Twitter with pound signs (#) in every status update.A hashtag is a keyword or phrase preceded by a pound symbol (#) that aggregates similarly tagged posts on Twitter. Hashtags make it easy to organise a stream of related topics.The use of hashtags has been around since Twitter launched in 2007, but they actually first appeared in online chat rooms before Twitter even existed. Since then, they’d made their way onto other major social networking sites like Instagram, Pinterest and Google+.Personally, I’m already starting to see hashtags on Facebook but citing people familiar with the matter, the Journal added that it is not a feature that will be introduced on Facebook anytime soon. Just how far the company has come along on the project is unclear.A spokesperson at Facebook did not comment on the Journal's report and told CBS News that the company does not comment on rumour or speculation.Facebook recently introduced a series of changes to its service. The social network launched Graph Search in January — a search engine inside of the social network. The company also unveiled a redesign of its News Feed and Timeline earlier this month.So why would Facebook add hashtags? It’s all part of the company’s battle with Twitter to become the best “personalised newspaper” in the world, as Mark Zuckerberg put it a couple of weeks ago when he unveiled the revamped News Feed. It could also help Facebook better integrate with Instagram which already uses the technology.The Journal speculates that the move could also help Facebook cash in on the potential advertising dollars that could come from adding the feature.So, how should we Facebook users prepare? You might want to brush up on your hashtag skills just in case #hashtagpractice.