Marks & Spencer has apologised after some customers were sent other shoppers' parcel tracking details.
One customer said he got more than 100 text messages with links to GPS locations and photographs of parcels on other people's doorsteps.
"Someone could have used that information to drive around and pick all those parcels up," he said.
M&S said: "Due to a technical error, a small number of customers received incorrect text notifications."
The spokesperson added: "The issue was quickly identified and resolved. We're apologising to [the customer] for the inconvenience caused."
They said only 1% of orders had been affected by the glitch.
The customer, who asked us only to use his first name, Tom, said a flurry of text messages started straight after he placed an order for some bedding.
"I kept getting loads of messages at once. There's over 100 texts and I had a few two days after I rang up and told them about it," said the 28-year-old from Essex.
"Luckily my phone was on silent but I could see all these notifications coming through and it was quite distracting. I can imagine for the other people this has been happening to it's pretty annoying."
He said he had been sent "pages and pages" of links about other people's parcels.
While no names or numbers or card details were included, he could see the location and GPS coordinates of where parcels were delivered as well as images of some people's parcels that had been left outside.
"Obviously the images of people's parcels, web tracking links, location of delivery and tracking information is probably somewhat sensitive information."
After complaining to the retailer, Tom received a message from M&S which said: "While we believe there is no risk of harm to customers, we sincerely apologise for any inconvenience caused - we are continually working to keep your personal information as safe as possible. I hope we have reassured you how seriously we have taken this."
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