Not long ago, I reminded young people who throw snowballs at automobiles that this is a dangerous practice. Shortly afterward an Arlington man chided me for writing that column.

"I have been living here for six years," he wrote, "and I think I have read that warning in your column six times. Apparently you write it every winter, but for the life of me I don't see why. I have never heard of anybody being injured by a snowball thrown at a car."

Inasmuch as I have myself been hit in the face while driving, I have a short fuse on this subject. I put the letter aside to be answered after I cooled off.

Meanwhile Toni Runge called me on Monday of this week. "You might be interested in what happened to me today," she said. "I was driving a friend's new car on Reno Road, and as I passed Harrison Street a snowball came flying through the open window and hit me right in the face. I lost control of the car, but instinctively my foot went down on the brake pedal and I came to a quick stop with no damage done. My two small children were uninjured. And the driver behind me reacted fast enough to avoid hitting my borrowed car, although he came within an inch of doing so."

"You were very lucky," I said.

"I know," Toni said. "Several years ago, some kids threw a snowball with a rock in it at my car. It shattered the windshield. My father had an even worse experience. He lost the sight of one eye for several months after he was hit with an egg. I think people just don't realize that they endanger lives when they throw anything at a moving vehicle."

"Did you see who three the snowball?" I asked.

"No," Toni said, "but I went back to the intersection afterward and asked a young girl standing there whether she had seen the incident. She said a group of junior high school boys from that neighborhood had been throwing at cars for several minutes. I reported this to the police in the hope that they could at least send a man around to talk to the students in the nearby schools, but I don't suppose they'll do anything."

"The police do try to maintain contact with the kids," I said. "But no amount of lecturing is going to reach all of them. Sometimes people become more safety-conscious as they grow older, but not always. And I guess young people just don't stop to think about the consequences of their actions. All they know is that it's a great sport to throw at a moving target, so they do it."

Toni's response was grim. "Suppose I had lost control of my car and run into that group of boys," she said. "If they're not concerned about endangering my life, how about the danger to their own lives?"

Parents, at the risk of sounding like a broken record, let me ask one more time: Have you cautioned your children not to throw at moving vehicles? If you haven't, why haven't you? Please do it today, and every time a fresh snow falls.