There was a project in Germany called the "Pulk Pranger" which basically translates to "gaggle pillory" or "leeching pillory. It was a software which scored each participant of a competition for the amount of leeching he/she did. If I remember correctly the rules defined that the first 4 entrants of a thermal are not leeching. All subsequent entrants received leeching points for the duration of their climb. Just like normal competition scoring there was a daily leeching score and an overall leeching champion at the end of the competition.

A quick google search shows the following github project:
https://github.com/thelightwasbrighter/pulkpranger