Umberto Eco used the Knights Templar history and lore in his novel Foucault’s Pendulum. At least two quotes from this book are occasionally used to summarize the meaning of all things Templar in modern culture.

Ci sono anche i matti senza Templari, ma quelli coi Templari sono i più insidiosi.
There are lunatics who don’t talk about the Templars, but those who do are the most insidious.

I Templari c’entrano sempre.
The Templars have something to do with everything.

See also:
Italian, please! – Italian language, culture, customs and Italy’s impact on civilization