Very inappropriate and needs to be addressed now. Best case this guy is just socially clueless; worst case he's looking for someone to groom for much more than a hug. He's obviously vindictive since he made posters of something a player asked him to stop, so addressing it directly with him may cause issues for your DD. If the seniors, and other players, are queued into this creepiness they have probably told their parents about it too. Maybe a "general concern" letter/meeting to AD from parents and/or team is best place to start, if nothing is done then escalate. Would definitely trust the players intuition. If he is just clueless, a word from AD to stop should solve, if he is something worse he'll probably be more convert about actions from there. Would make sure DD knew to avoid any isolated encounters and to watch out that her teammates do the same.