Chaplin
Better off silent
I think Sylar is tracking the heroes as well...remember in his apartment he had a very similar map with strings and all that Chandra had...but his had other people on it (Nathan Petrelli was on his, not Chandra's). He only knows about the ones he has researched....and his map was US based so I don't think he's aware of Hiro yet. Which is why Hiro is able to survive and basically round up these guys.
Sylar is like the Anti-Chandra...he's searching for the heroes to kill them, while Chandra was searching for them to prove his theory. The question is still, who the hell is Sylar and what's his story?
That still doesn't explain why he chose to attack the waitress and not Hiro. How can he be aware of this waitress whose only power appears to be a strong memory, but not aware of Hiro, who has probably got the biggest power of them all.