From torrent guide
Hit and Run: This is per torrent and it indicates that someone downloaded a torrent (hit) but as soon as the torrent finishes the user didn't seed back to others, but rather disconnects (runs). To avoid Hit and Runs, each torrent must be seeded for at least 72h (not continuously of course) or a 1:1 ratio (The amount of GB you downloaded, must be equal to the amount of GB uploaded), whichever happens first. You are allowed a maximum of 40 Hit&Runs total. After that point, your torrent downloading rights will be revoked and you won't be able to download from us. In case you dont want/can't seed, you can use your seed bonus point to zap them (make them disappear) and continue downloading.