I have login/signup popups on my site which are in hidden div by default. According to http://stackoverflow.com/questions/1547426/google-seo-and-hidden-elements googlebot should NOT see it.
But Google Webmaster tool says that keywords "email" and "password" are top keywords over the site.
Why it is so? Why google bot sees them?
Should I worry about relevancy of top keywords at all?
Open your site in the Lynx browser it is a browser that displays only text and this is what Googlebot sees also
Also check the Google Webmaster guidelines scroll down to Technical Guidelines and you will see this text
Use a text browser such as Lynx to examine your site, because most search engine spiders see your site much as Lynx would. If fancy features such as JavaScript, cookies, session IDs, frames, DHTML, or Flash keep you from seeing all of your site in a text browser, then search engine spiders may have trouble crawling your site.
Yes, Googlebot will see the text since it's in the HTML. However, it will probably know that it is hidden text, and thus may not give it a very high priority. Users searching for the text in hidden elements would be less likely to see your page.