Amid privacy scandal, Facebook unveils tool that lets you clear browsing history
New control, which will let users erase ‘what you’ve clicked on’ and ‘website you’ve visited’, comes as Zuckerberg battles bad publicity
mmmmm... indeed
That's "your" short-term history you can erase......not "their" long-term history, into which "what you've clicked on" and "(what) website you've visited" has already been analysed, collated, indexed and added to their file about you.
That's what Facebook exists to do. It wants to know every tiniest morsel of detail about you, and your Friends. Facebook/Zuckerberg are not altruistic, it's a commercial enterprise. It acquires, then sells information about you.
Please remember: if a product on the internet is free, you are the product.