Given the task definition and input, reply with output. In this task, you will be shown a passage. You need to write a fill-in-the-gap question based on your understanding of the events that might be inferred from the passage. Your question should be answerable based on the passage and only have one correct answer. Show the gap in your question with a _ .

ISIS has threatened Twitter founder Jack Dorsey and his employees after the site removed accounts linked to the extremists. Twitter confirmed to Daily Mail Online that the company was working with authorities to verify the seriousness of the threat which claimed employees' necks are 'a target for the soldiers of the Caliphate'. The chilling warning, written in Arabic, featured a picture of Dorsey in a gun's cross-hairs and the Twitter logo. It was posted on Sunday on an anonymous site based in Poland which is used by programmers to share code. Dorsey, who is worth an estimated $2.5billion and lives in California, made no mention of the threat online on Sunday as he tweeted his 2.87million followers.Twitter confirmed to Daily Mail Online on Monday that the company was working with authorities to verify the seriousness of the threatThe threat, featuring a picture of Dorsey in a gun's cross-hairs and the Twitter logo, was posted on Sunday

The message then appears to address Dorsey directly and _ employees.