An elderly couple who had a wall built around their home for safety have been repeatedly targeted by burglars using an adjoining BT box as a "useful ladder", a policeman said.
The couple, from East Acton, west London, have a 10 foot wall around their home which has been effectively reduced to four feet owing to the "thoughtless" placement, Inspector Aaron Clarke said.
He said the telecoms giant was "enabling criminality to happen".
However, BT said it had followed "all legal and planning restrictions" and moving it would not guarantee preventing further crimes.
In early October, three men smashed their way into the house with the couple, both in their 70s, inside, Mr Clarke said.
The suspects grabbed possessions before escaping by hopping back over the way they had come. Since then, there have been two attempted burglaries.
Mr Clarke said: "The box is relatively new. It's the view of the couples' son that the problems started when the box was installed.
"BT are enabling criminality to happen. Even if it was moved away three feet, we wouldn't be having these problems.
"It has been a frightening experience for them. It would be for anybody to have three people force their way into the house.
"Home is supposed to be the place where we all feel safe and they're at the time of life when they should be enjoying retirement and enjoying being home."
After complaints, BT reportedly told a neighbourhood officer it would cost an estimated £50,000 to remove the box.
A BT Openreach spokesman said: "Our cabinets are usually welcomed for the faster broadband they deliver, so we're disappointed to hear that this one has been used in this way.
"When we choose a site for a cabinet, we follow all legal and planning restrictions and we get approval from the Highways Agency to make sure any local concerns are considered.
"Unfortunately, it would be costly to move it and it would involve disruption for hundreds of broadband customers in the area.
"Moving it would also not guarantee crime prevention."