I was surprised to hear of the change (I heard about it while watching Obama's inauguration). Apparently the government believes that ex-presidents are now living longer and making lots of money after they leave office and thus able to afford to pay for their own protection.

Personally, I think it's bullshit to make the ex-presidents pay themselves. Sure, they'll make millions of dollars after leaving office BUT they were way underpaid for their time in office. Being the U.S. president is arguably the most stressful job around; with all the money that this country pisses away on other projects, we can afford to pay for the security of former presidents for as long as they live.