In a symbolic stance against its business model, Amazon has stated it will not permit behavioral ad firm Phorm to scan its webpages for targeted ads.

UK-based Phorm works directly with ISPs to build profiles of user interests, based on their overall web surfing behavior, and serve relevant ads to them across participating websites.

The company suffered hard times last year after a series of melodramatic Congressional hearings about potential privacy violations in partnerships between ad firms and ISPs. A number of partners deserted it, and before year's end the entire US-based executive team took leave, followed shortly thereafter by UK CEO Hugo Drayton and CFO Lynne Millar.

The technology that enables Phorm to categorize users anonymously is marketed as Webwise. In a recent statement, Amazon UK wrote, "We have contacted Webwise requesting that we opt-out for all of our domains."

Last month, the Open Rights Group wrote to chief privacy officers at Microsoft, Google/Youtube, Facebook, AOL/Bebo, Yahoo, Amazon and Ebay — urging them to opt out of Phorm, the BBC reports. So far, Amazon has been the only firm to respond.

But according to Executive Director Jim Killock of the Open Rights Group, sites like LiveJournal, mySociety and Netmums have already committed to block Phorm's technology. "We expect more sites to block Webwise in the near future and also ISPs to drop plans to snoop on web users," he added.

In January, a constellation of marketing and ad associations partnered to create unified, consumer-friendly guidelines for behavioral targeting. Two months later, Phorm launched a newsletter meant to tackle the "distorted reception" of behavioral targeting in general.