Raj Samani, chief scientist at soft- ware security giant McAfee, said: "Those heading to Butlin's this summer are probably very excited for their holiday by the seaside".
However, the booking reference numbers, lead guest names, holiday arrival dates, postal and email addresses and telephone numbers in 34,000 guest records may have been breached, Butlin's warned.
It is understood that the data breach occurred this week, when criminals gained access to the company's systems using a "phishing" email.
Butlin's insisted that "no financial data has been compromised".
Butlin's has set up a "dedicated team" to contact guests who may have been affected.
Butlin's MD Dermot King must've been doing the full regretful bottom lip puff when he said: "I would like to apologise for any upset or inconvenience this incident might cause".
The company is unsure as to how many of its 34,000 guests had their information stolen in the phishing attack and has not yet found evidence of fraudulent activity.
Ms Paulley added that human error was the "greatest single point of weakness" in organisations' security.
PANTO-STYLE HOLIDAY CAMP COMPANY Butlin's has admitted to a data breach that saw an "unauthorised third party" make off with customer data.
The incident has also been reported to the Information Commissioner's Office (ICO).