The European Parliament in Brussels, Jan. 12, 2023. Tech giants, including Meta and Alphabet, are spending lavishly on splashy billboard ads, courting on-the-fence politicians and bulking up their ranks of lobbyists in Europe as several countries weigh teen social media bans. (Ksenia Kuleshova/The New York Times) By VIVIENNE WALT In November, Kim van Sparrentak, a Green Party lawmaker from the Netherlands, grabbed her headphones and headed for the exit of the European Parliament building....