Watch out, Twitter. Over the next few weeks, Facebook will introduce clickable hashtags designed to organize posts by topic. It’s a natural move for the company, which noted that hashtags are already all over Facebook as well as its photo-sharing service, Instagram. Taking the extra step of making them clickable will make it easier for people to search by topic, said company executive Greg Lindley. Posts with hashtags will still be subject to each individual user’s privacy settings. The hashtag rollout for desktops should be complete in the next few weeks. It will take longer to deploy the hashtag feeds on mobile apps.