You need to seed your torrents for a minimum of 2 days[48 hours] or upload back what you downloaded. If you don't do that the system will auto remove your download ability.
If you start seeding the torrent again the system will give you again download ability.

Let's say you download a torrent that has 3GB size. You either seed it until you make 1:1 ratio on it [upload 3GB back on that torrent] or seed it for 2 days[48hours].
You can go into your Account Page[just click your name in the top-left corner], go to Completed Torrents and you will see a table there will all the downloaded torrents.

DeNeDe_Snapshot_2016-06-19_185001.jpg

In the image above the user violated the rules. He didn't seed the torrent until had 1:1 ratio and/or for 2days[48hours]. So the system flagged him at HnR/Mark.

The check only affects Users and Power Users. Anything above that has immunity.
Also you can remove your hit and run warnings in exchange for 300 karma points. The option will appear last in the table. After that you need to wait for the site to update itself. [once every 15mins]

Cheers!