I'm a big tennis fan and follow the sport pretty closely. What Serena did, IMO, went beyond the bounds of acceptable behavior for any sport. Not only did she spew some pretty foul language for all to hear, she also threatened a linesperson with physical violence. I don't know much about hockey, but I know that in the NFL (a sport I am truly passionate about) language like that directed at an official will more than likely get you fined. A threat of violence will get you tossed out of the game (which I think should have happened to Serena).

For the record, I love Serena. She is amazingly talented and a fierce competitor. I root for her every time she steps out onto a tennis court, and will continue to do so. I totally get that she was caught up in the heat of battle and lost her head. But IMO a mere fine is actually letting her off easy. A suspension would not have been out of order.