What happened
"Found by Google" products are items Google discovers by crawling your site rather than pulling from your submitted feed. They show up in Merchant Center whether you asked for them or not.
Google has published two methods, surfaced by Search Engine Roundtable. The cleanup path: apply a Pause attribute rule, and Found by Google items auto-archive after 14 days. The prevention path: add the data-nosnippet attribute to product pages, which stops Google from discovering those products via crawl in the first place.
One is a broom, the other is a lock. Most stores that have this problem need both.
Why this matters
Your feed is deliberate — you chose every product in it, wrote the titles, checked the prices. Your crawlable site is everything: discontinued products still resolving, wholesale-only pages, duplicates, landing pages that were never meant to be shopping listings. When Google merchandises that second set, your store is represented in Shopping surfaces by listings nobody QA'd. A retired product with an old price is a bad first impression you didn't know you were making. And because these listings sit outside your feed workflow, none of your usual checks — title rules, price syncs, availability reviews — ever touches them.
That said, don't reflex-nuke everything. For a store with a thin feed, Found by Google items can be exposure you'd otherwise miss entirely. The right posture is a product-by-product decision: archive the junk, keep anything that's a legitimate listing you simply hadn't submitted — and then submit it properly, so you control the title and data instead of Google's crawler.
Handle data-nosnippet with care. It's a snippet-control attribute with effects beyond Merchant Center, so scope it to the specific pages — or page regions — you genuinely want out. Blanketing your product template with it is how a cleanup becomes a visibility incident.
What to do about it
Audit Merchant Center for products you never submitted
This week, open Merchant Center and look for Found by Google items. List what's there: retired products, test pages, wholesale-only items, duplicates of feed products. You can't decide keep-or-kill until you know what Google decided to sell on your behalf.
Set the Pause rule for the junk
Apply the Pause attribute rule to the items that shouldn't exist as listings, and let the 14-day auto-archive clear them. Calendar a check after the window passes to confirm they actually left — cleanup you don't verify is cleanup that didn't happen.
Apply data-nosnippet only where 'never a listing' is permanent
Discontinued lines, wholesale-only catalogs, internal pages — those earn the attribute. Anything that might become a real product listing later shouldn't get it. Prevention is for categories of pages, not a default you spray across the site.
Put a quarterly recheck on the calendar
Crawl discovery doesn't stop because you cleaned up once. Every site change — new templates, resurrected URLs, staging leaks — can seed new Found by Google items. A quarterly fifteen-minute look keeps Google's guesses from quietly becoming your storefront.