Definition - What does Sua Sponte mean?
Sua sponte is a Latin term that means "of one's own accord."
In the context of the law, sua sponte is typically used to indicate that a court is making an action voluntarily. This is opposed to courts acting at the request of a plaintiff or a defendant.
A court will only make actions sua sponte under certain conditions.
Justipedia explains Sua Sponte
Conditions that could cause a court to make a dismissal sua sponte include a lack of prosecution, jurisdiction issues, failure to comply with established legal procedures, etc.
So, essentially, even though the courts are there to serve the public, there are times when they can act independently. However, it is much more common for a court to simply follow the normal protocol of addressing complaints and having trials in accordance with the needs of plaintiffs and defendants.