The Haiku Stairs are illegal and there is a chance you will get fined $1000 if caught. It's an amazing hike for sunrise which means starting at 3AM and hiking past security (they can warn you but not stop you). You can decide if it's worth it or not.

From the link that has directions: UPDATED 1/1/2022: Fines have been reported as approximately $1000, with people receiving them recently. Security has been upgraded and there is now not only security but also a frequent (but not constant) police presence. Police waiting at the top of the hike to book hikers is very uncommon but has happened on a few occasions. Basically, it is a high-risk hike, illegal and you may get fined