A reader pointed out to me that sun tea has come under recent criticism for potentially providing ideal conditions for growing bacteria. I was unaware of this concern, but wanted to pass it along to you. Read more here.
Personally, I will continue to drink sun tea. I've done so my whole life and never had problems. However, I will pay more attention. If it's "syrupy," as mentioned, I'll toss it. And, I won't keep it around for long.
Drink at your own risk, I suppose.