This project has largely disappointed me in many ways. I know HN doesn't care much about software licensing and that kind of stuff, but there are many legal issues behind the project that remain unsolved and have remained unsolved for majority of the project's lifetime.

1. The people behind Tox don't seem to be the copyright holders of their logo as admitted by one of the main developers[1]. The logo is the one also used on their website.

2. Tox project is now attempting to (falsely) claim to be the copyright holders of the logo.[2] Wikimedia Commons deleted the project logo for legal concerns, and to date it remains deleted.[3] There is no concrete proof for Tox's copyright claims on the logos, while there's pretty concrete proof that the project indeed does not hold the copyright on the logos. For those unaware of how our legal system works, "works without license" are considered copyrighted work of the author (e.g. anonymous user on linked /gd/ board).

3. Creative Commons licenses are also incompatible with their choice of software licensing, GPLv3+,[4] which means they cannot legally redistribute current logos under the current licenses with Tox software even if they were copyright holders to those logos.[5] As far as I know, the logos are already being redistributed with the software.

4. The documentation also cannot be legally redistributed with the software, and in theory nobody outside the project has practical freedoms to modify the documentation.[6] "I'm le troll! :-)" was most likely added by the developers.

5. Because of the above mentioned issues, Tox cannot be accepted to Debian GNU/Linux repositories because of DSFG guidelines.

6. The above mentioned issues also create false advertising; "Tox is both free for you to use, and free for you to change. You are completely free to both use and modify Tox."[7]

7. A developer quit the project because of other serious issues in the project.[8][9] The developer criticized the design of DHT (distributed hash table) used to find users, which leaked a lot of data about users. There's a large reddit thread about these DHT issues somewhere too, but I seem to be unable to find it myself right now.
Fortunately, the leak was patched a long time ago. Unfortunately, the patch was a large hack which the Tox developers solved by reinventing the wheel and reimplementing Tor onion routing.

8. I haven't verified this (so don't count on me), but the Tox core (or core + clients?) is now ~100k lines of code. It's not entirely lightweight per se, which was one of the initial goals as far as I remember.

9. Another minor thing that upset me was that during Tox's conference talk (forgot which conference, but it was related to YouBrokeTheInternet), the speaker forgot to introduce himself and what he was doing. This probably led to some confusion.

10. Possibly controversial too, but the first radio talk show Tox was introduced in was... could I say, maybe slightly cringeworthy. Or something. See it for yourself.[10]

Sorry if I went a little bit too political, knowing the rules. I wanted to point out these issues to let you know how everyone involved in the project can be a help.

[1]: https://rbt.asia/g/thread/40445107#p40449131 - you can scroll down and read the replies too
[2]: https://commons.wikimedia.org/wiki/Commons:Deletion_requests...
[3]: https://commons.wikimedia.org/wiki/Commons:Undeletion_reques...
[4]: https://github.com/irungentoo/toxcore/blob/master/COPYING
[5]: https://www.gnu.org/licenses/license-list.html#ccbysa
[6]: https://github.com/Tox/Docs/issues/7
[7]: https://tox.im/
[8]: http://www.tox-chat.com/2013/08/tox-developer-fed-up-quits.h...
[9]: https://github.com/irungentoo/toxcore/issues/493
[10]: https://www.youtube.com/watch?v=IdR3SVcBbq0

Disclaimer: I'm not the author of any of the links above. It's what I have gathered from numerous discussion threads Tox has had on 4chan.