Quantum enforcement is the usage of Quantum Enforcement Devices (QEDs) to stall or prevent quantum travel in other ships. Due to the nature of this technology, certain jurisdictions will require licenses or for the operator to be a part of certain organizations. Generally, quantum enforcement includes two techniques, quantum snare, and quantum dampening.
The Quantum snare is the primary utilization of the QED, intended for large-radius events (approx. 10–20km), and will create a "bubble" around the ship. Any ship that is within the bubble will be knocked out of Quantum travel, and ships passing through will be pulled out of quantum travel as well. Engaging the Quantum Snare requires significant charge-up time, and maintaining the snare requires a lot of power while generating large amounts of heat.
The current game implementation is fairly limited at best, as the functionality for properly scanning travel routes and quantum events does not yet exist. If you want to interdict a ship it has to pass close enough to you. In the case of the Mantis (the only ship currently with Snare functionality) this will be 20km in each direction. If the ship gets into range, your QED will pull out the ship automatically. You will interdict everything passing through your snare (if the ship is travelling in the Quantum tunnel) even teammates and party members.
After you've enabled your QED, you can choose to charge your Quantum snare. This generally takes 30 seconds before you can engage your Quantum snare. For the duration the Quantum snare is active, the QED will require a lot of power and ship will emit a considerable amount of IR and EM. If you choose to then disengage your Quantum snare, the QED goes into a cooldown mode for 2 minutes during which you cannot utilize the QED in any way. 
Other things to consider
- For an unknown reason the Quantum snare will only pull out ships traveling in the Quantum Tunnel. This tunnel opens after the ship traveled roughly 2000km - 4000km after departure, depending on the Quantum drive used. Because of this, sitting in range of a spot below this limit will cause you to only catch inbound traffic.
- It is suspected that bad server tick rates may cause target to bypass the Quantum snare bubble.
- Nothing is static. Moons in the game rotate and if you are on the same physics grid you will rotate with them. Places like Everus Harbor or Grim Hex orbit a planet and are constantly rotating. Catching inbound and outbound traffic there is almost impossible. Always consider these places to be at every point of their orbit at the same time.
- Don't turn off the Snare if you pulled out a ship. It cannot jump away since the Snare is also jamming it. Just stay in the 20km range.
- Interdicting ships is illegal and you will get you a 7500aUEC fine. You can stay outside of the range of a Comm Array to combat this issue but it is not always guaranteed you won't get a fine.
- The Snare can not be used in the "greenzone" of a station. These will reach 30km out from any station or outpost.
- Snare-Event-Markers will be shown to all your party members. This makes it easy to engage a target fast.
Quantum Dampening is the secondary usage of the QED, preventing the activation of quantum drives within a short range while active (approx. 4000m). In contrast to the Snare, Dampening can be activated instantly, trapping lone unwary ships as long as they are within its radius.
Since the current implementation of the snare makes it jam the quantum drive as well, ships with both a snare and dampener functionality (Mantis) rarely use the dampener. The only benefit for them is that it can be instantly engaged (the snare takes 30 seconds to charge).
Ships without the snare functionality (such as the Cutlass blue) can use the dampener to keep targets from jumping away within the 4km range, but can most likely not pull targets out of quantum travel .