"Google has indexed tens of thousands of HP printers, which are publicly available from anyone with an Internet connection, but could also be attacked by hackers with malicious—albeit hilarious—intents.
Granted, the search engine indexed the printers without knowing necessarily what they are or that they're probably meant to be network-internal only. The onus of blame should probably fall on the hapless IT person who set up the printer that way rather on the search engine. (Trying the same result in Bing displays no results at the time of writing.)
If you type in the following on Google: