Here are your options:

1. Robots.txt - http://support.google.com/webmasters/bin/answer.py?hl=en&answer=93708 - easy option.
2. Noindex tags - http://www.mattcutts.com/blog/google-noindex-behavior/
3. Removal request - https://support.google.com/webmasters/bin/answer.py?hl=en&answer=59819

I think knowing why you want the follower counts would help us provide a better way to obtain the data.

For example, I look at profile metrics/authority when I'm setting a new profile up in a specific vertical. BUT, I know that I can use Topsy's twitter search to identify those authoritative tweeple. They have a nice hover-over feature that will show you follower stats for each user talking about the search query. I can also use TweetAdder to do this manually. I don't need to slow down, neigh,  I would rather not slow down to record or even read a list of follower counts.

If you truly do want the data for bulk processing within a site, some sort of new tool.. then pulling it directly from Twitter may be the answer. It really depends.

In my ten years, I have definitely heard of this happening. It's a bigger risk when your SEO provider has a private network of sites.Heck, I have even heard of people holding this over their clients; "If you quit you will lose all your traffic/rankings."

It's really no different than people paying YP for a directory listing, they are billed for "Search Engine Marketing" monthly and when they stop, the link is removed.

I view SEO similar to web design/creative -- if you pay us, it is yours, you retain ownership and that is the way it should be.

I hope that works for +1 button clicks as well! Makes sense though if it truly does just reflect popular search behavior. Sometimes I think it would be better to perform keyword research on auto-complete over the finicky and inaccurate Google KW tool.

You mentioned you did not want to use one provided by search engines.

This is by far the best list of both web-based and server side sitemap tools I have found to date,

http://code.google.com/p/sitemap-generators/wiki/SitemapGenerators

I think knowing why you want the follower counts would help us provide a better way to obtain the data.

For example, I look at profile metrics/authority when I'm setting a new profile up in a specific vertical. BUT, I know that I can use Topsy's twitter search to identify those authoritative tweeple. They have a nice hover-over feature that will show you follower stats for each user talking about the search query. I can also use TweetAdder to do this manually. I don't need to slow down, neigh,  I would rather not slow down to record or even read a list of follower counts.

If you truly do want the data for bulk processing within a site, some sort of new tool.. then pulling it directly from Twitter may be the answer. It really depends.

Here are your options:

1. Robots.txt - http://support.google.com/webmasters/bin/answer.py?hl=en&answer=93708 - easy option.
2. Noindex tags - http://www.mattcutts.com/blog/google-noindex-behavior/
3. Removal request - https://support.google.com/webmasters/bin/answer.py?hl=en&answer=59819