The most common blackhat method right now is abusing the Google Indexing API.
Operators will use fake schemas (like JobPosting or BroadcastEvent) on standard pages to trick the API into accepting the submission, forcing a crawl within minutes. The catch?
Google drops those pages from the index almost as fast as they add them once they realize the content doesn't match the schema or lacks actual authority.
You can force the crawl, but you can't fake the retention.