Why is the yahoo answers lightbulb filled with toxic mercury?

[Lemanski's Ghost]

Whenever asking a question a lightbulb pops up. But it's one of those filled with toxic mercury. Is Yahoo trying to tell us that our ideas are poisonous?

 

[♥♀ Dee ♀♥]

Is there a Y!A lightbulb? Please explain...

EDIT: Isn't mercury what goes in thermometers.... tungsten goes in lightbulbs?