Yeah, I found a great one in .net. If you used HttpWebRequest to fetch a url that had an invalid GZIP header the app would hard crash. This is because the request and decompression was being handled on a threadpool thread. An exception would be thrown and no one would be around to catch. Fortunately this was in a web crawler so it took quite a while to build a repro case and an exact diagnoses. I believe it was fixed 4 or 5 years after I reported it in 2008.