Twitter #Thatsafrican and #thingsdarkiessay hashtags after users complained that they found the hashtags offensive. There are allegations that Twitter removed #NaMOinHyd from the trending list and added an Indian National Congress-sponsored hashtag. There are numerous tools for adding content, monitoring content and conversations including Twitter's own TweetDeck, Salesforce.com, HootSuite, and Twitterfeed.com. , fewer than half of tweets posted were posted using the web user interface with most users using third-party applications (based on an analysis of 500 million tweets by Sysomos). In June 2009, after being criticized by Kanye West and sued by Tony La Russa over unauthorized accounts run by
Twitter follow an account and who a user has chosen to follow is also public, though accounts can be changed to "protected" which limits this information (and all tweets) to approved followers. Twitter collects personally identifiable information about its users and shares it with third parties as specified in its privacy policy. The service also reserves the right to sell this information as an asset if the company changes hands. While Twitter displays no advertising, advertisers can target users based on their history of tweets and may quote tweets in ads directed specifically to the user. A security vulnerability was reported