This script initially sets the player notoriety with pirates to -500 then continues to monitor the notoriety and sets the relation accordingly.
You will now gain notoriety by helping pirates that are being attacked
If you want to play as a pirate or with the pirates as allies then this script is for you.
Simply download and extract, then follow the instructions in the readme.txt - the rest is automatic.
IMPORTANT - If you are currently running an older version of Friendly Pirates you must remove it first as follows:
1) delete the files setup.friendly.pirates.xml and friendly.pirates.xml from your ..\X3 Reunion\scripts folder
2) start your game (and load from the save you wish to continue from)
3) go to the Script Editor and select GLOBAL TASKS
4) note the PID number on xxxx:friendly.pirates:null and select it
5) press the 'delete' key
6) check the PID number is correct
7) select 'yes' and press 'enter'
now save your game, exit to desktop and install the new version
Download v4.01 here and be sure to read the new enclosed readme.txt
Enjoy

Edit: v4.01 fixes problems noted in some of these posts, specifically it will now work with Cockpit Callback installed.