As persuasive systems seep into our lives on the back of technology, the need for counter-persuasive technologies becomes more apparent. Many users are not aware of design elements that exploit their cognitive biases and encourage them to act against their own self-interests; Project-Machete was created to level the playing field. It seeks to limit the ability of persuasive technologies on the Amazon shopping platform to persuade users into making impulsive or extrinsically influenced purchases. It removes biased plays to item scarcity, selectively reveals recommended items, counters biased encouragement to buy new over used items, and encourages shoppers to think critically about whether a purchase should be made at all. Project-Machete achieves this through JavaScript driven DOM-tree manipulation inside an extension for the Google Chrome web browser.
Ethics in Persuasive Technology (PT) is a largely fragmented, standardless, and treated
as an afterthought. In the analysis of a literary review conducted in 2019 regarding the
past 13 years of literature in PT, it was found that only 66/375 of the analyzed papers
on PT mentioned more than 1 sentence regarding ethics. Of those 66 papers, 43 of them
mentioned ethics “In passing” without discussion [
While we humans have had countless years experience with face-to-face encounters
with persuasion, deception, and coercion, we have not yet had a century of
face-toscreen encounters. Consider somebody in the midst of buying from a salesperson in a
brick-and-mortar shop. If this salesperson was constantly muttering phrases under their
breath, urgently trying to steer you towards or away from certain products, or
relentlessly trying to up-sell you, you would be naturally suspicious of them! This is
where Project-Machete (PM) comes in, to aid those who are not yet as suspicious of PT
in a sales setting. PM’s implementation and concept were inspired by Benjamin
Grosser’s “Facebook Demetricator” chrome extension [
As a content-script style Chrome extension, PM is allowed to inject a JavaScript (JS)
and a CSS file into a set of pre-defined domains. This is what allows PM to modify the
raw HTML of Amazon’s pages. At a high level, PM’s depersusification process goes
through 3 stages 1) Page Identification, 2) Item Identification, and 3) Item Mitigation.
Page identification matches specific pages on the Amazon domain using regex, once a
page is recognized stage 2 is entered. This stage uses JS and Amazon’s implementation
of best practice web-development (classes for common style elements, ids for special
items) to collect various PDEs on a page (i.e. recommended lists, the ”buy-now” button)
for stage 3. In stage 3, PM addresses PDEs as an item to either remove or modify.
Notable PT elements that are removed include the ”Buy now” button and the ”In stock”
report. The “Buy now” button is an example of reduction [
Though Project-Machete is incomplete, it is functional and version 1.2 is currently deployed to the Chrome Web Store. As user feedback is gathered and more PDEs are identified, the list of elements to address in later versions of PM grows. A detailed list of technical issues for Project Machete can be found in the repository’s issues on gitlab. Chief among those are: Current reliance on RegEx, inability to buy kindle e-books, and a small UI issue introduced by inserting the HTML to collapse recommend lists on a page. 3.1
Ethics & Future Work.
Though it was not initially considered as such, by engaging in counter-persuasion, PM
itself takes on elements of PT. With this in mind, PM could be seen as a piece of PT
that dabbles in coercion and deception. It cannot be denied that PM infringes on user
agency. It removes some elements, decides buying used is preferable to buying new, it
hides elements by default, and forces a user to fill out a form before making a purchase
without first asking if this is their desire. What could be argued though is that because
Amazon infringed on user autonomy first through selective reporting, relentless
upsells, etc. - PM is simply leveling the playing field. For example, the ”in stock” report
is deceptive in that it fails to report used items, and chooses whichever niche option is
of lowest stock to report on; is PM being deceptive when it removes Amazon’s
deception? Should counter-persuasive technology be considered coercive/deceptive if
it removes such elements from other platforms? This is a question out of the scope of
PM, all the same, PM recognizes that infringing on user agency and engaging in
deception/coercion is a poor way to promote ethics in PT and counter PT alike. Future
work on PM will seek to bolster user agency, & bring attention to it’s goal: “To provide
a shopping experience on Amazon that is free of influence from PDE’s implemented
by parties with conflicts of interest in the buying process”. By making users aware of
this goal & how it is achieved, their acceptance of PM would imply recognition and
voluntary exposure to the techniques PM employs. Looking at PM this way, its coercion
can be seen as similar to the example provided by Smids regarding the seat belt [
A primary concern regarding PM’s aim is that users may end up with the idea that justifying a purchase on moral fronts is as simple as filling out a form and waiting a minute. PM does not currently, and has no plans in the future of evaluating the worthiness user-provided purchase justifications as this would open the door to even more ethical concerns. However by not doing so, users may use whatever reasons to “justify” their purchases while still getting PM’s “approval”. This is where the problem is, if PM’s form is considered a mere ”moral approval stamp” by users, they may end up seeing any answer they provide as justifying, and as a result buy more because of this. This undesirable potential side effect is why user education should be at the forefront of PM’s future work. A user that understands the purpose and value of the form will be critical of their own provided reasons.
Taking into account PM’s goals of increased user agency (beyond enabling/
disabling the extension) and education, PM favours the guidelines proposed by Spahn
regarding ethics in PT [
Acknowledgements: I wish to thank Dr.Vassileva for encouraging me to submit to this conference. I would also like to thank anonymous reviewers for their feedback and suggested resources. Finally, I would like to thank Benjamin Grosser for his Facebook demetricator. The idea for Project-Machete would not have been formed without his groundwork.