In the context of this discussion, I think it might be appropriate to
share the following. A few days ago I had a brief conversation with a
(non-Wikipedian) user on social media regarding a fundraising banner
they were seeing. In their case they had an additional concern with the
banners (apart from "making Wikipedia unusable"). They wrote:
"<...> I find it more than a little creepy that wikipedia is tracking
how often I visit."
Curious, I asked if the popup said anything about their browsing
behavior, and it did (citing a snippet they have shared with me):
"Hi, reader in Canada, it seems you use Wikipedia a lot; that's great!
It's awkward, but this Tuesday we need your help. This is the 10th
appeal we've shown you. We don't have salespeople. Thanks to the
donations of 2% of our readers, Wikipedia remains open to all. If you
donate just $2.75, or whatever you can this Tuesday, Wikipedia could
keep thriving. Thank you."
We want to make the Wikimedia Sites better for you by learning more
about how you use them. Examples of this might include how often you
visit the Wikimedia Sites, what you like, what you find helpful, how you
get to the Wikimedia Sites, and whether you would use a helpful feature
more if we explained it differently.
This contradicted my intition about the privacy of anonymous Wikipedia
readers. It seems like some behavioral data is collected and then used
to target readers for fundraising in some ways.
Is it specified in more detail anywhere what kind of behavioral data is
collected, for how long it is stored, how it is associated with a
reader's device(s), and what behavioral data is used in the context of