WASHINGTON  - Serena Williams knows her way around a tennis court, but the 15-time Grand Slam champion got a crash course in golf fan etiquette on Friday. World number one Williams tweeted that she was taken to task by an official at the US PGA Tour's Honda Classic in Palm Beach Gardens, Florida, for taking a picture of Tiger Woods in action. "Apparently u can't take pics. This security for mad and yelled at me," Williams said on Twitter, although she still managed to get her shot of Woods on the 17th tee and posted it on the social networking site. "I need to learn golf, didn't know I knew so little," she tweeted. "Apparently u can't take pictures of golfers. In my Defense, peeps always take pics of tennis players," she said, adding a puzzled face emoticon.