Customers were stunned to receive a massive Southern Water e-mail containing details of up to 400 people who had applied to receive a free water butt from the firm.
Names, addresses, and dates when installation teams would visit customers' propert
ies were accidentally copied into a mass e-mail, sent on Monday morning.
The incident sparked fears that the information could leave householders vulnerable to rogue callers posing as installers.
Kit Cartier, 55, from Fawcett Road, Southsea, was just one of hundreds affected.
She said: 'I think it's worrying. It leaves it open to crime, because there may be a very small element who might be trying to make hay out of this.
'They've got so many details, they could turn up and pretend to be with the company.
'But those details could be used for other things too. There may be other repercussions, so I'm concerned.'
The residents on the e-mail list had been taking advantage of an offer to install free 190-litre water butts in a bid to promote efficient use of water in Portsmouth.
More than 5,000 households applied to the scheme – run jointly with Portsmouth City Council – between July 7 and August 31, and about 1,000 homes were due to have the butts installed by the company.
Portsmouth South MP Mike Hancock said: 'I'm appalled. If they have done that then they ought to put out some explanation pretty quickly, because they shouldn't give that out in any circumstances. Somebody should have checked first.'
Southern Water apologised for the error, but said it was the contractor employed to install the butts, Straight plc, which had messed up.
Chief executive Jonathan Straight said: 'We're in the process of issuing an apology but don't believe any harm has come of this. No sensitive information has been revealed.'
Police said no-one had made a formal complaint.
The full article contains 342 words and appears in The News newspaper.
