What is legitimate big/super affiliates such as BizRate.com doing about parasiteware issues?

The ones I know that're pretty powerful in terms of generating traffic and sales for merchants and do not steal affiliate commissions are:

Bizrate.com
DealTime.com/shopping.com
FatWallet.com

Others I come accross pretty often:

all-internet.com
onlinestoresmall.com
activeplaza.com

What's their position againts the parasiteware?

I'd think that some of them (many not listed here)are in pretty good position to pressure merchants and networks to take action against their commissions stolen.

Do you know what they're doing?