well "bad" is in the eye of the beholder and since we already hashed the whole "touchy-feely" side of ppi ethics a while back no need to go there again.
If you do not have a problem with downloading tons of pirated materials, infecting them and then passing them on to unsuspecting boobs
(which we all are from time to time) then ppi might just be the right thing for you.
it's more like the grey fuzzy area where phishing is definitely black as night
so if your comfortable with that then get cracking on reading this forum -everything you need to know is right here