@john32123666
After some tests it seems that I actually have an upload issue. I've tested my download at 876 Mb/s, but my upload is stuck at 0.2 Mb/s 
At the beginning of the week I did not have this trouble: I remember having freeleeched a torrent and uploaded more than 40 gigabytes within a few hours.
After 2,5 hours of freeleech, I have 31 leechers, who are at ~ 22 % completion; thus I'll continue to seed until everyone reaches 100 %…
(And I have now to solve my upload enigma.)
I concur with the observations above: sine 1~2 days most torrents are in trouble… 
@mihaig110 Same thing happened to me exactly 8 days ago. The takedown was so swift (maybe 1 or 2 minutes) that no user got enough time to even attempt a connection!
As usual my torrent (2 vids) had thumbnails, description & screenshots, which usually gets through with no problem…
During the 80 minutes preceding that very takedown, I had two more (older) torrents also DMCAed!
(Three unrelated torrents deleted in that short interval of time 
!!!)
@john32123666
No, I definitely have a real trouble; at the beginning of the week my upload would reach 200 Mbps at moments.
I'll keep investigate. Maybe a damaged optical-fiber cable?
Thanks for taking the time to read and answer me. 
@john32123666 You're right but this rule remains theoretical.
I was wondering whether it's possible to implement a mechanism that would automatically reject a picture that is less than 200 pixels wide (or high) for example. 