Britney is reportedly threatening to cancel her "Circus" tour after receiving death threats from an anonymous stalker, according to UK Yahoo!.
A source told Britain's Look magazine: "Britney received some anonymous death threats over the phone and in the mail, and her worst fear is a kidnap plot against Sean or Jayden. She's been having terrible nightmares ever since then and she wakes up in the middle of the night crying out for her boys.
"She told her head of security and he thinks it's a lone stalker. Her paranoia has reached fever pitch and she's wracked with fear."
Other sources claim Britney is "distraught" after hearing harsh reviews regarding her "Circus" tour performances.
"Britney is under so much strain, what with relentless performing, the bad reviews and the worry over her boys. It all got too much and she screamed at her team, 'I can't do this any more, why are you all torturing me?' She ran out of the room crying."
Pretty sure the "anonymous" stalker is the British Bitch.