A hiker in Utah was confronted by a cougar- after he apparently inadvertantly walked/ran past a couple of her cubs.
She followed, and at times CHASED him for 6 minutes, and he got it all on video. (Caution- language on the video!)
The cougar lunged at him several times too!
You have to give the guy mad props because he kept his cool, and didn't run (which could have made the cougar attack him). He calmly walked backwards (UPHILL, mind you), while using his voice to deter the animal.
Pretty cool customer, this guy. I'd have shit my pants, and passed out right there on the trail - haha