Max Clifford tells me Simon Cowell is so shaken by what happened on Saturday night that he will now be strengthening security at his home in West London.
He already has a security team looking after the £9 million property but he feels he needs to take extra care after the break-in.
Max Clifford says Cowell is thankful this was a warning sign that didn't end up being any more dangerous.
Leanne Zaloumis will appear again at Isleworth Crown Court in Middlesex on June 12.
The charge against Leanne Zaloumis, that was read out in court, said she intended to "inflict grievous bodily harm upon a person therein and at the time of committing the said burglary had with you a weapon of offence, namely a broken house brick".
Leanne Zaloumis, who is charged with trespassing on Cowell's west London property, spoke only to confirm her name and address - Brownhill Road, Catford.
She was remanded in custody at West London Magistrates' Court for her case to be heard by a crown court judge.
Leanne Zaloumis, 29, was remanded in custody as she appeared in the dock at West London Magistrates' Court accused of breaking into Simon Cowell's Holland Park home wielding a broken brick.