Twitter has added two-step verification to increase its security after all the recent hacks into high profile media accounts, but you should go sign up for it right this minute — because everyone's vulnerable to password attacks these days. Or maybe not right this minute, since there are some reports that Twitter is a little overwhelmed and others have reported the two steps aren't showing up for everyone. But at some point in the very near future, you get on that. Here's why, even if the new cellphone hiccup seems cumbersome.