This is a great thread. There isn't internet in the world of Obscurato but I totally know which sites each character would use.
Larkin is Facebook, he loves keeping up with family pictures and posting activities he does with his grandkids. He is definitely one of those people who posts endless "My granddaugher is the best in the world" pics all over his wall.
Dionisia is an avid Pinterest user she uses it for inspiration for crafts and also pins cool armor and weapons all day, she would also have a Tumblr blog where she comments on social issues and adds perspective from back in the day. Definitely an informed grandma who teaches the younger generation.
Ram would be an avid Twitter user, sending out thoughtful nuggets of wisdom and silly gifs. He would also be really into Instagram posting artsy images of his daily life.
Joseph would be all over snapchat, posting ridiculous nonsense all day.
Kartar would be on Reddit in the science and philosophy subreddits, and engaging in discussions all day. They would also have a YouTube channel dedicated to cooking, with a mix of cooking videos and discussion about food.