Click on preferences under the Acquisition drop-down menu:

Click the Sharing folder and remove all folders that are classified as shared. Limit uploads to the minimum.
The minimum for acquisition is 1 (one) upload per person. Under "Also share all files," uncheck both the
"Currently being downloaded" and "Previously downloaded" boxes. Uncheck the "Allow freeloaders to download files." This will further limit file-sharing capabilities. This prevents people who do not upload from downloading from you, essentially removing uploading capability from one peer (you) to another:

Please respect your jurisdiction's copyright laws: