Google indexed your internal search results

Google indexed your internal search results
Found /search?q=cheap+viagra type URLs in the index. Spammers had been hitting the client's internal search, and every query generated a crawlable, indexable results page. Thousands of garbage URLs, some with injected spam.

The fix:
— blocked /search and the query param in robots.txt
— added noindex on the search template as backup
— removed any internal links pointing into search results

Internal search pages are infinite, thin, and abusable. They should never be indexable. This is one of the oldest holes and it's still everywhere.

Watch for filtered list pages disguised as search — same rule applies.