Yes, you should validate your followers. Two reasons, firstly to see if there's anyone too shy to @ you who may be worth following. Secondly, to cut spammers etc off at the knees. Thirdly to stop you looking like a total arse.

If I see that you have thousands of followers, I assume one of two things
a) You're a "sleb"
b) You're a multi-level-marketer, spammer, self-help guru or politician. In which case, I don't want you showing the world how awesome you are by following.
c) You're a feed, in which case, I'll add you to my feed-reader.

I regularly trim my followers. I'm only interested in those who are actually interest in me. If you're following 14,000 other people, you're not really following me, are you? You may just as well be on the public feed or have specific searches set up.

Like yourself I am right onto keeping an eye on followers; as you suggest i) to see if there is anyone worth following and ii) to chop spammers off at the knees - that's like a community service surely.

And I'd agree that where the following number is excessive that attention is not going to be forthcoming but still I can't say that I'm that bothered if "bob from boston" is following me even if he does have 14,000 followings and is convinced he is an "SEO Guru."

Quite simply maybe Bob does get something out of following me, only he knows (and with the new Twitter lists managing that volume will only get easier surely).

The point I think I'm getting towards is that who I follow matters most to me. Reciprocity from clever, meaningful and conversational folks is greatly appreciated but by no means expected. Indeed I follow people whom I consider thought leaders and most assuredly do not expect them to follow me back.

But does validating me as a human have any real benefit to the followed party and does it place a barrier to following by interupting the otherwise simple process?

As I mentioned on Twitter earlier to @graphiclunarkid I can see some benefit in validating bots as there are some that one may want to be followed by; services that one accesses by Twitter messages. One suggestion is to only allow following by bots where you follow them but that assumes you need/want to follow.

I am beginning to think that a process not dissimilar to OAuth whereby a token is passed to a service which enables their bot to follow/interact may be useful - but that thinking is by no means fully formed - yet.

Love "sleb" BTW