"Regarding Debian, then what's the difference with Trisquel? Ok, it's
based on Ubuntu.
Then Compared with GnewSense? I know this distro has a full list of
de-blobed programs.
Is that actually pointless?"
Naah it's not really pointless.
First, let me talk about Debian, the operating system (not the Debian
project).
If you only use the main repo, it's true that it's not much different to
gnewsense (though gnewsense is normally quite outdated, so the current debian
stable release will be more up to date) but there are some free programs that
endorse non-free add-ons.
Afaik, iceweasel (Debians version of firefox) does that; or think of add-ons
for kde... stuff like that!
So gnewsense would be safer from a freedom perspective, but you can use
debian in freedom, if you watch out (or don't install any add-ons).
Now, the Debian project is hosting the non-free repos and offering it to the
users;
it's a very controversal topic and often discussed in this forum, but in
general, people here consider this unethical.
Also, some people say that the debian installer sometimes suggests the
installation of non-free software if it's required for the hardware to
function; maybe this has changed though, and i never experienced it myself.
So, it's up to you what you think about this.
Anyway, most important thing is that you run only free software on your
computer.