Google (GOOG) announced this week it will be "rolling out a series of enhancements to AdSense's contextual targeting capabilities, which will more accurately match relevant ads to Web pages."

Good! Maybe now we can get past one of the Internet's oldest problems: embarrassing ads placed by contextual targeting.

Click through to see Google's worst contextual ads ever →

"Contextual targeting" is Google's practice of scanning its publishing partner's Web pages for certain keywords or phrases and then using those words and phrases to find the right to ads to serve to visitors of those pages. A post on a group of cute puppies could turn up a Google ad for adopting puppies.

But sometimes this process goes horribly wrong.

For example, back when terrorists attacked tourists in Mumbai last year, In.com headlined a story "Terrorists killed the man who gave them water."

Google's ad for the occasion?

"Terrorism: Pursue a certificate in terrorism 100% online. Enroll today. Ads by Google."

Whoops!

Thing is, there have been plenty more awkward incidents like that -- way too many, really.

We've collected some of the best worst examples here.

Each of them are entirely explainable -- a video about US Airways airplane crash would draw an ad for US Airways tickets because of the obvious keyword match -- but given Google's technological prowess, each are ultimately inexcusable.

In a post to an official Google blog, we believe that with these changes users will start to see even more relevant ads, advertisers will generate more attractive returns by finding the right users, and publishers should make more money over time."

But let's be honest. Woojin could also probably could have added: "And maybe we'll embarrass ourselves and our partners a whole lot less."

Click through to see Google's worst contextual ads ever →