IMO When a customer defends X company about that companies errors and mistakes than that is a white knight.

For example the error 401 and 601 is not a customer error is Square enix error
And people Still defends this ? That's a white knight.

When you see the general Shout Blatantly hijacked from gamers by gill sellers and Square don't do anything about it and people defend it? That's a White knight

When we report boots and hackers and Square don't do anything about it, and people defend it? That's a White knight

So if you after seeing all the boots , the gill selling SHOUT (not even whisper) SHOUT and Square not doing anything about it and you defend this, then you sir are a White Knight.
It's clear isn't it?