This trophy is completely luck based making the online extremely frustrating if you are unlucky with Ubisoft's matchmaking. The best method to earn this is:
Press the Select (Options on PS4) button and go to Online.
Turn off Online Invasions (which resets your prestiege).
Exit and wait for the game to finish saving.
Turn Online Invasions back on.
Wait for 10-20 minutes; if nobody invades you or if you are hacked/tailed repeat the above steps.
When being tailed don't pull out your phone (pressing Square) and try to stand somewhere open. Give the person at least 10 minutes to finish tailing to make sure it counts for the trophy. Some people say you can hunt them down, but personally, I recommend letting them finish the tail so you are sure it counts. If they invade and don't start the tailing before you detect them it doesn't count for the trophy.
You have to be invaded and tailed by 5 other players so you are the mercy of Ubisoft servers for this trophy. Many players will try hacking so this trophy can take awhile. Also keep in mind you cannot be on any mission, side mission, crime alert, etc. to be invaded. You have to stay in free roam. Also if someone calls Blume Corporation (similar to when someone calls the police 2da07e.png but purple instead of red), ignore them as this increases the chances of being invaded although it does not guarantee they will be invading to tail you.