Interesting comment above about whether 'they' can tell what you are doing at the time.
I recently contacted BT about my router dropping its wireless connection now and again, and more importantly that the reset button didn't appear to work. Anyway, that aside, the reply included this:
In response to your query I would like to advise you that I have logged into your home hub manager though our systems and have been able to change the wireless channel on your BT home hub to a higher channel and this in turn will transmit a stoner signal.
I assume he means 'stronger' but interesting nonetheless.