Woops, wasn't me, promise. Abuse@yahoo yes, good. Also try a Google search for known issues regarding each one, trackers, addware, spyware etc. You realy need to get the 'trackers' out of your system and implement better security(user accounts, parental controls, windows internet security settings etc,). Or they'll return from other bot outlets. Not all porn sites are hostile in this way but a maximum security should be used if needs must. Don't panic, your getting them because they've got a link to you, you can undo it with a bit of a browse and maybe a code or two.
There are numerouse accounts of people being threatened with bills, fees, subscription costs, ignore all of it. Accept nothing but what you want on your Comp.