One time, when I was a rank newbie, I dry hopped a Pliny clone in a 5 gallon carboy with about 5 ounces of whole hops. And they sat there on the top while the wort bubbled through the hops and foamed out the airlock threatening to push the cork and airlock out of the carboy*. I ended up dumping the mess in a sanitized 7 gallon bucket, and it turned out fine (except that the yeast blew out all of the aroma), but it was a learning experience.

Charlie
*That was also before I learned to let fermentation finish before dry hopping. lol
"Yes officer, I know that I smell like beer. I'm not drinking it, I'm wearing it!"