It is not a problem at all.

We simple to not submit user profiles to Google in our site map and we also block the profiles from crawling, because we optimize this site for content, not user profile information.

If you want to search by user user name, Google is not the best way, in these forums. Other forums might permit Google to crawl individual profiles or include them in their site maps, but we don't since most users are interested in the content via Google, not searching for their own posts.

There are better ways than Google to find your own posts. You can easily get them from your profile page too.