Celebrity mum Myleene Klass is "aghast" after being warned by police for waving a knife at teenagers who entered her garden.
The TV star and Marks & Spencer model was in her kitchen, with her daughter upstairs, when she spotted people peering into her window just after midnight on Friday.
She grabbed a knife and banged the windows before they ran away.
Hertfordshire Police officers warned Klass she should not have used a knife to scare off the teens because carrying an "offensive weapon" - even in her own home - was illegal.
Klass told Sky News in a statement: "My family are totally fine and I thank the police for being so re-assuring and comforting.
"However, I was left shocked and surprised to be told that a private individual in the privacy of their own home runs the risk of committing a criminal offence if, out of fear for their own safety and their loved ones, they grab something with which they could defend themselves if an intruder enters their home.
"I totally respect British law - but surely everyone has the right to self-defence in their own home if they are in danger?"
Her spokesman Jonathan Shalit said the former Hearsay singer was "utterly terrified" and was stepping up security at the property near Potters Bar.
He told the Sunday Telegraph: "Myleene was aghast when she was told that the law did not allow her to defend herself at home.
"All she did was scream loudly and wave the knife to try and frighten them off."
Klass' fiance Graham Quinn was away on business at the time of the scare.
It came amid calls for greater rights for people to defend themselves against intruders on their property.
In December, Munir Hussain was jailed for attacking a man who tied up his family in their home. He and his brother used a cricket bat to beat one of the intruders.