Most mturk HITs are hosted either on s3.amazonaws.com or mturkcontent.com. This leads to many userscripts being active at the same time, which makes a lot of clutter and can also cause accidents. This script creates headers for userscripts that will only activate on the HITs that they are intended for, eliminating the need for activation filters or script deactivation.
To use this script, first edit the user details section at the top of the script to your own preferences. To generate a header for a HIT, open the "HIT Details" pop up for that HIT and click the "Copy HIT Data to Clipboard" button. The header will look like this: