[shiandow]

Overall that seems decent as far as privacy is concerned, though there are 2 things I don't like about it.

1. It relies on an 'aggregation service', which you'd better hope is trustworthy because they seemingly get all info about what 'impressions' you had and what 'conversions' you caused.

2. This is the browser acting on behalf of advertisers. It's nice there's a way for people to help companies benchmark their ads, but this really shouldn't be something a user agent does without being explicitly told to.

[buildfocus]

It uses multiple aggregation services, each of which get only partial data for each event, such that no individual service can track you, even if they wanted to. Initially the two aggregators are run by Mozilla and ISRG - your privacy is at risk only if you think both are malicious and actively sharing all the data between each other to track you.

As the number of aggregators increases this gets better - as long as you trust at least one aggregators involved then your individual data remains untrackable.

Also, in general if you think Mozilla is likely to _actively_ lie to you to steal your data and track you, you're probably using the wrong browser in the first place and the aggregation service makes little difference.

[freeAgent]

Given how our data circulates around the web’s data brokers, it doesn’t take a stretch of the imagination to see that the risk of aggregators colluding the de-anonymize people is actually quite high.