There has been a lot of controversy surrounding the hackability of Motorola's DROID X (which was released today), especially with the recent news of the inclusion of an eFuse that may or may not brick the device if a user attempts to hack it. The rumor originated a couple of days ago at My Droid World and says that Motorola included the eFuse security system in the DROID X that will check the ROM and bootloader of the device. If it detects that either has been tampered with, the eFuse will essentially brick the DROID X, requiring that it be sent in to Motorola to be repaired. This would essentially make the phone unhackable, especially since many customers would probably avoid buying the device simply because it could not be loaded up with custom ROMs.
Others have argued, however, that the eFuse technology has been used in devices in the past and that all of the worries about bricked DROID Xs are nonsense. A Google search for OMAP and eFuse reveals that the technology is part of the M-Shield hardware security technology on TI OMAP chips. This means that devices like the Motorola DROID and Milestone also contain the eFuse technology. This leads many to believe that the DROID X will follow the same fate as the Milestone, becoming a near-unhackable handset.
After considering both sides of the issue, I think that it would be kind of ridiculous for Motorola to include a component that would brick a device if it was tampered with. Their security on the Milestone seems to be doing its job of blocking hackers rather well, so there's no need to implement an extra layer of protection. The DROID X launched today and I'm sure there will be a few brave hackers that will attempt to break the DROID X's security, so we'll find out who is right soon enough.