Walk around Block 137, Yishun Ring Road and you will find 13 closed-circuit television (CCTV) cameras mounted in the 12-storey block.
Residents have installed them for such reasons as deterring against theft, warding off loanshark runners and keeping tabs on difficult neighbours.
But what many people do not know is that it is illegal to install these cameras outside their flats without permission from the town council and Housing Board.
A resident of the block knows this all too well. He was once ordered by the town council to remove the two security cameras that he had put in place outside his unit.
He had installed them to ensure that his neighbour, with whom he has a hostile relationship, does not do any mischief to his flat.
The resident, who wanted to be known only as Mr Richard, said the feud began after his neighbour refused to clear the row of potted plants at the common corridor which extended to the exterior of Mr Richard's flat.
Earlier this year, the feud became so bad that the neighbour smashed the cameras that Mr Richard had put in place. Mr Richard claimed he had to spend "thousands of dollars" to replace them.
Details of this incident was reported in The New Paper in March, but Mr Richard claims that his neighbour's harassment has not stopped.
He told The New Paper: "I felt threatened and insecure as I live every day with the nagging feeling that he would take revenge."
So Mr Richard felt that the only way he could protect his family was to have surveillance cameras to monitor his neighbour's movements.
Mr Richard said: "I approached the town council and was told that having one camera is legal as long as it does not invade the privacy of other units."
However, he felt that one camera was not enough. In January, he installed two CCTV cameras, one pointing at his main door and the other pointing towards his window.
In February, he started to receive several summons letters from the Nee Soon Town Council, advising him to remove both cameras.
Mr Richard brought up his concerns to the authorities and received a six-month approval from HDB for the installation of one camera from March till September.
Now that this time period is up, Mr Richard has to remove the cameras, but he is refusing to do so.
He said: "I will be put in more danger when... I have to remove both cameras. If I'm harmed, who will take responsibilty?"
In March, his neighbour admitted to destroying his cameras. He also approached the town council to ask Mr Richard to remove the cameras.
Four of the 13 households in Block 137 with CCTV cameras facing the common areas told TNP they were not aware that they have to seek permission to do so.
One resident, who gave her name as Ms Lynda, 27, installed a dummy camera that she purchased from Mustafa Centre because it was cheaper than the actual one.
But she admitted that she did not realise that she had to seek permission from the authorities to do so.
Ms Lynda said: "If the town council asks me to remove it, I'll just do so. But I'm worried that the loan sharks will come back again."
Similarly, another resident, who wants to be known only as Ms Nani, said that she did not know that a permit is required for the installation of CCTV cameras.
But some households are aware of the rules.
Ms Anna Loh installed a security camera outside her flat because there had been incidents of loan sharks harassing residents a few years back.
The 52-year-old housewife made a police report and was given official approval by the police to have the camera installed.
Mr Mohamed Firus, 47, a logistics coordinator, installed a dummy security camera outside his flat a few years back because of loanshark activities in the block.
However, he knows that before installing such a camera outside his flat, he has to apply for a permit from the authorities.
Mr Firus said that while he did not apply for a permit because it is just a dummy, if the town council were to ask him to remove it, he would just show them that it is not a real one.
"This camera is for safety reasons as my wife and kids will be alone at home while I'm away for work," he said.