Crashman :
Actually it's routinely done to track kiddie porn. But while the police will actually go through the effort of contacting the ISP and locating the modem when it comes to kiddie porn, they simply don't care about stolen personal property.
every time someone goes on the internet you are given a unique number ( and ip address ) which belongs to and isp which has been given in a set range. go to speedtest.net and youll see what isp your on.
within that isp is a record of every website you go to and every file you download and what images you look at by listing urls.
there was a case of people paying for kiddy stuff on a credit card which linked them to an address. loads of perverts got caught on this.
every email is also recorded in the uk and US I assume as well as phone calls, mobile calls and faxes - the US had Echelon and its simular to the UK system which also helps catch terrorist activity. - it picks up on certain words which alert authorities to the activities.... its just wether or not someone does anything with the information, but its recorded non the less.
The data storage on this is huge - terabytes and terabytes with huge processing power.
also were are photographed in the uk more than people can imagine - every road almost has cameras and in London you are photographed no less than 1000 times if you travel from one side to the other.
as a laptop can be transfered to separate locations and different access points - the only thing that is unique when connecting to the internet is the mac code of the network card - wether it be wireless or hard wired - each one has a unique address called a MAC address. This also releates to a mac address on a adsl line. Each customers Mac address for broadband on a telephone system is unique as well as a separate one in the pc. The MAC address is joined to the telephone number it is on.
The ISP can tell you when you came on line, what you downloaded, what pc it was on - what websites you looked at, what you did and for how long.
Adobe activate their software on the serial number of a hard disk.. For example there is only on seagate st8220 with a serial number of wefrrt9945449. If you install a pirate copy or the same software twice Adobe know by the unique hard disks serial number, model and manufacturer by a software program built in to its installer. If its a pirate copy Adobe record it.
Im know Windows holds this information too in a secret log and there are parts of Windows which we cant reach without forensic tools which the police and microsoft have privy to.