Grumpy Grammar Grinch Grouses...

[Chile Pepper]

That versus which is a style question. US publishers tend to prefer the distinction, whereas the Brits almost never do--they freely use which as both restrictive and nonrestrictive. I personally edit my authors following the that/which distinction based on my publishers' expressed preferences, but strictly speaking, which is grammatically correct.

[kjay]

"That" is used with a restrictive clause, "which" with a nonrestrictive clause. For that reason, it's important to use the correct word; therefore, it's not simply a matter of style, in my opinion.

[PinkBike]

Not to mention "that" as opposed to "who."
"That" describes a thing, "who" a person.
i.e. "Cancellara is the one who gets my heart racing."

OBTW today I was watching last year's Ghent-Wevelgem race and Phil Liggett, who is the King of Malapropisms, said the peloton was going to have to "redress the situation." Maybe they could do that AFTER they address the situation.