My understanding is that Trisquel receives a cut of the ad revenue when
Trisquel users view ads on DuckDuckGo, and this parameter is used to indicate
to DuckDuckGo that a user was referred from Trisquel.
It looks so: https://help.duckduckgo.com/privacy/t/
It might be a fingprinting risk, since not very many people use Trisquel, but
only for DDG, not other sites.
If DuckDuckGo honors its privacy policy, it uses no cookie (unless the user
changes its settings) and stores neither user agents nor IP addresses:
https://duckduckgo.com/privacy#s3
In those circumstances, I do not see how the "&t=" URL parameter would raise
a privacy issue. It probably only increments a counter.
