Reply to DJ's and their Tracklists

Is it common for a DJ to not reveal their tracklists? I figure what makes us/you YOU, as a DJ, is your taste in music and your efforts in digging. I'd like to believe that digging would help put you ahead of your game as it allows you to play out truly unique tracks and really slap the dance floor on the ass with some novelty.

>not a DJ
>you guys are DJ's

What's your take on this? Do you guys hide your tracklists?