Having gone to synagogue since childhood and teen camp with Shia for a fair chunk of my life, I can say affirmatively that he is in fact an unrepentant liar, cheat, and all around dick.
I will always treasure the day at camp when he was making fun of my best friend's brother, who was like my brother. After a few days of this, it was enough. I told him off, explaining that not everyone gives a shit about his fame, and that if he's going to be an outright asshole all the time, it was just indicative of what a sad, lonely person he really is. Then I told him that if he bothered my friend again, I'd feed him own testicles for breakfast in the mess hall. Let us just say that he left my friend alone after that.
Pretty much all I can say positive about the guy is that when we were little his mom was always super nice to me and all the kids. Sad he never got any of that from her.
Hm... So, do we believe this tale? Can anyone corroborate?