Of course, he could still be "placed" by Harbinger or Mysterio's SP.

Imagine teleporting in a colossal tree right into your enemy's lap!

Who's the object of "Groot [...] can't be moved" then? Groot cannot move himself.

These types of nit-picking have been getting waaaaaaaaaaay too common lately, so I'm goning to put my Deputy Hat on and put a stop to this before it gets out of control:

You're incorrect, Joe. Groot can't be moved. Period.

Groot can't be moved.
Says it right there he can't be moved, if he moves himself is he being moved? YES.
I'm thinking you are making up things or no understanding the English language very well.

While I agree with your sentiments, Mr. Pot, I would like to introduce you to Mr. Kettle.

It's hard to tell from the tone, but I think it's possible you have just been introduced to Mr. Sarcastic.

Obviously, it says that right in the power. But why can't Groot move if his speed is increased? Your ruling does not seem to be based on anything in the rules. The power reads as if it's trying to keep Colossal Groot from being TKed or carried by other characters. If the design intent was for Groot to be completely stationary, it should be phrased that way.

He's moving, not being moved.

Actually, I have master's degree in English, which is clearly more than the sub-high school education of whoever writes the error-ridden rules and powers.

and once he has moved what has he done? MOVED.

Because if you used his speed value to move him from point A to point B, that would be Groot being moved. His SP prevents Groot being moved, so it can't be done.
It's based on the part of the SP that says Groot can't be moved.
No, it doesn't. YOU are reading that into the power with no actual basis for doing so.
It is.

If you're so insistent on this approach, here's the first sentence under "Moving Your Character" on page 3 of the rulebook:

When you give a character a move action, it can be moved a number a squares equal to its Speed Value.

Your figures don't move on their own (if they do, then I've been getting some bad boosters). They have to be moved by you.

Thank you, Flatmatt, for finding actually evidence as to the intent of the power.

it still seems a little odd, given that other special powers don't get meta, but the wording is definitely the same.

Even with your mastery in english I still feel you are wrong.

The special power says:

There is no implied object. I read it like, here's the power name, it's not optional (ie can't be turned off), Here's the traits Groot now has (Colossal damage, 4 range, and can't be moved (by ANYTHING).

Giving Groot +3 to his speed value and then MOVING groot ends up with Groot having MOVED, even under his own powers.

As far as I'm concerned the rule book shouldn't even have to say when you give a move action a character can be moved as a basis. Because simple understanding of the english language is, after something goes from a moving state to a stationary state it moved.

The rules further wouldn't make sense if they said, "When you give a character a move action, it can be moving a number a squares equal to its Speed Value."

Now would they..

Photosynthesize.

Is this grammar lawyering?

Seriously though.

Joe is your argument that Groot can move himself because it says that "Groot cannot be moved" as opposed to explicitly saying "Groot cannot move himself" (or including that text)?

Why would you assume that not being moved would not include Groot moving himself. It's an exclusion so it would be all encompassing. If there was meant to be an exception (such as Groot can move himself) then that exception is what would need to be stated in the SP, IMHO.

As is, I don't see why it would need to state that the exception doesn't apply.

It's like a rule telling you what you don't need to do. It's unnecessary and confusing. The fact is that 99 out of 100 people would not find the issue you're finding or have a problem with it. I am a lawyer, so believe me I find ambiguity in everything, and I don't think it needs to say that the "Groot cannot be moved" includes Groot moving himself.