Find Out the way they spy me

I have similar questions to this thread : http://forums.majorgeeks.com/showthread.php?t=190533
but it is closed, so I open a new one.
I have irritating neighbours who spy me on what I see on the net. I have not turned on wifi, I only use cable dsl. I have also changed modem passwords, turned off the snmp/cwmp etc etc...
I can hear neighbours talking about what I see on the net. I have bought a device like this http://www.amazon.com/Strong-TM341-...id=1427987704&sr=1-2&keywords=sound+amplifier to check that they are talking on what I visit on the net. And they are able to see what I am visiting at the exact time I visit it...!!! But before calling police, I would like to read some opinions on what they can use to see what I am downloading. Should I check for anything in the external telephone box? I should provide very strong clues to the police because ISP do not do checks I had read in other forums and I am not from the US or northern Europe to enjoy good services.

I can hear them clear, they were even able to know that I have changed my ISP password. They were able to know when I didn't had internet connection because I have put wrong ISP password!!

 

"I have not turned on wifi, I only use cable dsl." not sure how this rules out hardware.

Physical security - as in, perhaps they've hooked in directly to your house/cable/router wiring?

 

I followed the instructions but I accidentally cleared the cache and then I decided to do a format, but I can still listen to them spying on what I see

I will give more clues
In 2011, I changed modem, I also did a format. I could hear them that they could not see what I download on the net for a few days.
But they found a way later.

I was using the old modem on my laptop that time. I noticed that they could not see the pages I was visiting with that modem.

But even if it is malware, I have more questions:
I moved for one year abroad for a postgraduate degree.
I used the same device there without doing a format.
I was downloading pages abroad that I am sure that they could not see them. For example I was entering my university page when I was abroad and they could not see it. I avoided to visit that page when I was back home for holidays. When the postgraduate was over, I visited the page from home and they saw it for the first time. I could hear it.

That's why I am thinking that they somehow found a way to see what I visit only when I use my home's connection.
They cannot check what I see when I use the same laptop/PC with another connection

 

Be careful of using your listening device! I know these can be built cheaply and easily. However their use beyond novelty items around your own property and family as a game or what not - any use on unsuspecting people may be a problem. And in a way you are reading them the same way you think they are reading you just with a different technology. Walk softly here.