Not in the "obvious in retrospect" way, but because browsers have been progressively blocking history-sniffing tactics for years precisely because advertisers were using it to identify visitors.
Did this research... establish better numbers around it or something?
>> However, this time around, since the data was collected from Firefox itself and not through a web page performing a time-lengthy CSS test, the data was much more accurate and reliable. Furthermore, the data Mozilla researchers collected is also about the same type of data that today's online analytics companies also collect about users — either through data partnerships, mobile apps, online ads, or other mechanisms.
>> The new experiment got underway between July 16 and August 13, 2019, when Mozilla prompted Firefox users to take part of this experiment.
>> Mozilla researchers said that more than 52,000 users agreed to take part and agreed to provide anonymous browsing data.
I regularly visit maybe 5 or 6? The rest tend to be random links from reddit or HN, I wonder if visiting a site like that once and never again is enough to help with that identification.
Another thought is I think it's obvious that if it's a site you log into and the URL has an identifier of some type then it's easy to identify you and that's why schemes to hide the URL could also be a privacy issue.