I was looking for a font in Google and at first I didn’t quite understand what was going on. My first thought was “Fuck, the fonts are gone!” Then a pause… Stop! I’m in Google’s search results. Really? Exactly!
If you’re looking for a popular font, it will replace its fonts in the results with the one you’re looking for. Take a look at the example of the georgia or courier font.
Now I’m sitting here thinking whether this is good or bad. When you expect such behavior, it’s good and useful, but when you don’t, it’s “Help!” and “What’s going on?!” Why make the user panic?