Did you know according to The Register that your browsing activity is being tracked and profiled by software on Virgin Media and BT servers and possibly other ISPs. BT did a trial run without users knowledge, the profiles are then passed on to Phorm no doubt for a tidy fee so that you are targeted with adverts of the relevant sites you visited....
.... imagine what would happen if the computer was shared, could this cause a family argument, think about it?
This could breech the Data Protection act of 1998 (c29) it depends if you agree to it or not Phorm warned by British Government, have you been asked to opt in or out?
Blocking all the cookies from oix, phorm, webwise & sysip will stop the cookies from downloading.... but not from you being profiled. To stop being profiled you have to bypass the system, for Firefox users you can download an add on Dephormation that allows the system to be bypassed by altering the cookie, it also notifies you if you are visiting a Phorm related site. Safari browser it is claimed handles the cookies differently bypassing the system, see Guardian article.
How Phorm works & When ISPs go bad. Phorm was formally 121media inc. Googling 'anti phorm' will bring results by the thousand. TiVo is similar in America see LA Times.
Whether the Firefox add on or Safari browser work's I can't say, it may well all be super hype to lead you down the garden path because...... whats the point of going to all this trouble and being profiled if you have your cookies blocked in the first place, it sounds all too shady, there's got to be more in it than that.