On Ygg (formerly T411), maintaining a healthy ratio (keeping your upload higher than your download) is mandatory. When you download a 50GB 4K movie, you must upload 50GB back to the community.
YggTorrent has hardened its security significantly over the last two years. Their backend scripts (often based on Ocelot or customized XBT Tracker) are incredibly good at spotting "Ghostleeching." yggtorrent ratiomaster