It’ll help! But hackers’ most valuable targets will still be vulnerable.
Twitter has "finally" added two-step authentication to all accounts (always with the "finally," tech writers). This lets you require a one-off text message code every time you log in. Nobody without access to your phone can log into your account; ergo, only you can log into your account.
This is progress. Google has two-step, as do Facebook, Dropbox and even Yahoo. Sure, Twitter probably should have had it a long time ago, and it will prevent some hacking. But it might not be able to fix the problem that caused so many people to call for this feature in the first place.
Many, if not most, large brands allow multiple people to have access to their Twitter accounts, but Twitter two-step only lets you add one phone number to your account. A lot of the accounts that have been hacked recently, including accounts associated with the AP, Burger King, 60 Minutes and The Onion, were likely managed by multiple people.
The higher the profile of the account, the more valuable it is to hackers, and the less likely it is to be managed by a single person. Here's a social media editor at NBC: