I've done just that. Here's the message I left with Google in their "we're sorry to see you go, please leave a message" box:
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Hi there.
I've heard about a lot of problems with Google plus, for instance:
http://www.zdnet.com/blog/violetblue/google-plus-deleting-accounts-en-masse-no-clear-answers/567
I don't want to use my real name online, for privacy reasons.
And at the same time, I don't want to have my gmail account (that I use a lot), blogger, or others be deleted because of a TOS violation in Google+ (that I barely use).
I'd rather use Facebook or Twitter instead of Google+, and risk a TOS violation there (due to using a nick rather than my real name, or other issues).
At least in that case I won't lose access to all my email, blog posts, etc at the same time.
I wrote more about this problem on my blog over here:
http://chmmr.blogspot.com/2011/07/concerned-about-google-identity-policy.html
And I'm sure you're aware of many other people complaining about this.
I was really interested in your Google+ service before, and was encouraging others to try it out, but your recent policy of deleting accounts has me very concerned, so I'm not going to bother with using Google+, and I'm recommending to other that they be really careful about signing up with Google+.
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Also I made sure that all my Google-related backups are up-to-date.
- Blogger - using their export function each week to save a backup to XML.
- Gmail - I'm using a mail client (kmail) in offline IMAP mode to slurp all my mails.
Google also thankfully has some other exporting services, if you're paranoid about losing your account with them.
More problematic is losing access to my gmail email address, but it's too much trouble/I don't know how to setup my own domain, email server, dns records, etc, so I'll take that risk for the time being. I'm also keeping track of all my logins/passwords/etc in a separate secure location, I don't rely heavily on websites "reset forgotten password" functions.