According to police in Arlington Heights, Ill., residents are being warned about spam e-mails demanding money and threatening those who do not comply with death.

Police said the scam e-mails, which first started showing up about eight months ago, told recipients they were being watched, and that they had to send $15,000 or $20,000, depending on the e-mail, to the senders, otherwise, they would kill the e-mail’s recipients.

Police said the e-mails were being sent as spam and that they were advising people not to respond.