system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] Could the Unbreakable Vow be used for criminal justice? Why isn't the Unbreakable Vow used more often?

For example a wizard named Jared McFogle is put on trial for giving underaged wizards and witches love potion and after his time in jail he has to take an Unbreakable Vow to not do anything illegal with a minor.  
   
You would think the ministry would love the unbreakable vow. Get convicted of not paying your taxes, well here comes the magical IRS with an unbreakable vow and a team of goblins to go over your finances.  
   
Force every death eater to take a vow of "I will no longer follow the dark lord or engage use the unspeakable curses"   
   
Where is the down side?
gpt
You can't force someone to make a vow. That's not how that works, whether it's magical or mundane. And binding reformed prisoners to death pacts isn't exactly in the spirit of rehabilitation. 

Besides all that, the answer to this question is the same as the answer to every HP related question along the lines of "Why doesn't X get abused more often?" Witches and Wizards have a reverence for certain kinds of magic for very good reasons. Basically, if you don't see everyone using it or doing it all the time, make one of two assumptions: It's either really hard to do right and/or it's really dangerous to get wrong.