> Our analysis revealed the fork-to-star ratio as the strongest simple heuristic for identifying potential manipulation. The logic is straightforward: a star costs nothing and conveys no commitment. A fork means someone downloaded the code to use or modify it.

This is just clearly...incorrect? You can both modify code without forking it and most software is distributed via a registry or binary download, which also wouldn't be represented in forks. For most projects, the number of forks is a lossy signal for how busy the contributor ecosystem is, nothing else.