weBlock claims to be an ad-blocker that runs on a server to save client-side processing power, but could secretly censor data at the deployer's disposal.

This is a collaborative project with lucasliebe and tiny-fish-T and is being developed within the scope of a course named DarkAI at HPI. The course's goal is to raise awareness about possible harms and threats of artificial intelligence and to provoke more critical thinking in handling software products.

This project consists of a client and server, which can be installed and run separately. Both actors require a working installation of Mozilla Firefox and Zsh or Bash. In addition, the client requires Node.js and Yarn and the server requires Python 3 together with python3-venv, Geckodriver (which is installed by downloading the operating system's respective executable and moving it into the $PATH), Make and GCC.

With the above requirements met, the install script can be run in bash or zsh, e.g../install.sh to install both client as well as server or with an argument client or server to install only the respective actor.

To run the client, go the the client/ directory and run yarn start. This will open an instance of Firefox with the ad-blocking / censoring extension loaded. The toolbar will show weBlock's icon, where the address of your server that has weBlock's server side deployed can be set. By default, this is assumed to be localhost.

Browsing with the extension loaded will behave normally, but you will notice a circle icon show up on the right side of the URL field for tabs with supported webpages (http(s), html).Clicking the icon once will put the ad-blocker to work doing it's best to remove advertisements and give you a preview of what content will be censored by coloring it red. Clicking it a second time will engage censoring and replace the red text with content the censorer (server) deems as friendly but still contextually relevant.

After installation you should change the variables in server/.env to match your desired censoring configuration. By default, you will find CHANGEME values so you can customize it to your desired content.

NEGATIVE_QUERIES should hold a comma seperated list of Google News search queries of articles with negative opinions about your topic. For instance, an option to promote opinions of the flat earth society could be round earth site:news.com, earth globe.

Similarly, POSITIVE_QUERIES should also hold a list of Google News queries but about articles that support your view, e.g. site:flatearthsociety.com when:7d.

More details about queries can be found inside the detailed guide below.

To make your censoring more precise, it is also recommended to add a list of CENSOR_REQUIREMENTS. These words (or synonyms of them) will be required to be included in a paragraph for it to be censored like earth, planet, sphere.

Run source server/activate, then server/scrape-postive -t && server/scrape-negative && server/run-backend and use the client as described above when scripts are ready (i.e. the prompt

setup done, waiting for connection

has shown up).

Before using any of the server's functionality, source the activate file in server/ in your bash or zsh shell. This will load the virtual environment the server lives in and greet you with the (weBlock-server) message in your shell's prompt.

weBlock's server side is managed by three executable scripts in the server/ directory, namely scrape-positive, scrape-negative and run-backend.

For the collection of data, weBlock relies on Google News to scrape recently published articles. Those articles in turn are then scraped for information used to train its natural language processing models and build a database of paragraphs used to replace censored content.

scrape-negative is used to collect examples for what is undesired by the censorer. It searches Google News with the comma-separated queries defined in the environment variable NEGATIVE_QUERIES in server/.env.
scrape-negative also clusters the scraped summaries with an implementation of random search. Random search requires a number of iterations, which can be set with -i and a sample size, set with -s, i.e. the number of clusters that will be in the resulting database. Both arguments have default values when omitted. Default for -i is 50 and default for -s is 5. The scraped articles are then used as negative examples in censoring, where the Word Mover's Distance of a paragraph to the scraped article's summaries plays a role in determining wether that paragraph should be censored.

scrape-positive is used to collect examples for what is desired by the censorer. It, analogously to scrape-negative, searches Google News with the comma-separated queries defined in the environment variable POSITIVE_QUERIES in server/.env.
If scrape-positive is run with the argument -t or --train, the resulting articles from this scraping are used to train a Biterm Topic Model with the parameters defined by the environment variables TRAINING_* as given in server/.env. Leave these parameters unchanged for fast but far-from-optimal results. Training is necessary on the first run, but can later be skipped to reuse the existing BT Model.
The Biterm Topic Model makes the key decision in finding which of the scraped positive, desired examples in the database will be used to replace a paragraph that is marked for censorship.

Both scrape-positive as well as scrape-negative have an optional argument -n or --narticles that can be used to define an upper limit for how many arguments are scraped per query. This argument defaults to 10 if omitted.

Note that Google search operators such as the site: or when: modifiers can strongly refine and empower defined search queries (e.g. when:7d constrains results to articles published in the past week). See this incomplete list of operators.

With data collection and model training done, the server now has sufficient data to act as weBlock's backend. To run the backend, execute server/run-backend. Once it's ready, use the client as described above.

Since this is a proof-of-concept prototype and focussed on the natural language processing side of the project, some features that would be significant for scalability and real-world use have been left unattended for ease of use, ease of installation, project size and human resource prioritization. These include, but are not limited to

• database & RAM: this project does not use a real database but instead simple text files and is strongly constrained by the RAM's size (e.g. the entire databases' contents may be loaded in RAM at times)
• server: the current architecture uses a simple socket for serving the (singular) client
• full performance optimization
• censorship of non-textual & non-html content (i.e. images, videos, documents)

As stated above, this project is aimed at raising awareness about possible harms and threats AI can pose and is therefore not intended for any malicous use or use diverging from this intention. This is also the reason why censoring does not happen in secret and "behind the scenes" as it could, but is implemented as a two step and manually triggered process on the client side and why censored and modified paragraphs are colored in red.