wilderness - 2:47 am on Mar 24, 2012 (gmt 0)
All those ancient big long bot lists do is slow your server down processing them.
In addition, those long lists promote the copying and pasting of badly formatted syntax to instructional-website after instructional-website prompting newcomers whom fail to grasp the concept of badly formatted syntax, into their active use.
"crawler" and "spider" will stop a vast majority that chose to ID themselves. There are about a dozen other names (synonyms)(which have been discussed here over and over) that most everybody agrees on.
After that, each webmaster must determine what is beneficial or detrimental to their own website (s).
I deny "Linux" in a UA, most others do not.
Malformed browsers with extra spaces or missing spaces will stop others.
Building such a list and keeping same list current is a viscous circle from a group standpoint.
There are simply too many variations and too many custom requirements to offer a "one-size-fits-all".
Many others prefer white-listing over black-listing entirely.