Mozilla has disabled the Avast Extensions listings at its Add-on store, following reports that these extensions spy on users.

The organization didn’t blacklist the extensions however, stating that they are still talking to Avast. So for existing users these extensions will still be active.

Wladimir Palant, a programmer working for AdBlock Plus, claims that the Avast browser extensions are essentially spyware. He has named Avast Online Security, AVG Online Security extensions, Avast SafePrice and AVG SafePrice as extensions that upload detailed browsing profiles of their users.

On its website, Jumpshot, a company acquired by Avast in 2013, actually praises its “clickstream data” product:

Incredibly detailed clickstream data from 100 million global online shoppers and 20 million global app users. Analyze it however you want: track what users searched for, how they interacted with a particular brand or product, and what they bought. Look into any category, country, or domain.

Spying on your users is clearly a violation of the terms that both Google and Mozilla make extension developers sign.

Palant also reported these four extensions to Google. Since then, extensions have only ever been removed from the Chrome Web Store after considerable news coverage.