Using the entitydata tag "NoAI" on arrows makes them gain a blue particle effect
What I expected to happen was...:
I expected nothing to happen because arrow physics don't count as AI
What actually happened was...:
the arrows I fired, like I said, gained a blue particle effect
Steps to Reproduce:
1. Place down a command block
2. Turn it to repeating and always on
3. insert this command: /entitydata @e[type=!Player] {NoAI:1}
4. fire arrows
Related issues
duplicates
Comments

Arrows do not have a
NoAI
tag. Any data you insert that could update the arrow would cause this to happen, which includes any invalid data, such as: