This is the 2095th most frequent Polish word.
nielegalnie
Illegally.
Here, 'nielegalnie' is used as an adverb to describe the manner of parking.
On parkował nielegalnie w centrum miasta.
He parked illegally in the city center.
In this context, 'nielegalnie' modifies the action of earning, indicating it was done in violation of the law.
Podejrzewany jest o nielegalnie zarobione pieniądze.
He is suspected of earning money illegally.
Here, 'nielegalnie' describes the manner in which the files were downloaded, showing action against legality.