And because you don't notice your PC infected by botnet s/w, does that mean you can expect to get a free pass from spam filters? Ad networks operate for profit,

And because you don't notice your PC infected by botnet s/w, does that mean you can expect to get a free pass from spam filters? Ad networks operate for profit, they are not charities, therefore they should invest the effort to secure their systems if they want what little goodwill that remains to not evaporate.