Could you prove where you were last night? Say for example, the police show up questioning you about a firearm you sold to an individual some years ago, and they want to rule you out as a suspect in a Monday night murder. How well could you cover your tail? Let's presume HONESTLY cover yourself, but you can expand in your responses if you wish. After some thought, the only evidence i have that i was anywhere last night would be a couple of cellphone calls and some interweb banking on my home laptop through my home's interweb connection. Beyond that nobody really saw me after maybe 9pm.