Ok so someone out of the blue has now started following you and even though you might not be that interested in their Twitter subject matter, out of politeness you follow back almost like returning the favour. Sometimes these phantom followers are on a mission to get as many followers as possible for what ever reason and as soon as you follow them they then un-follow you. May be its a status thing where it looks good having 500k followers and only following only 15. Anyway there is a way to spot if any of the people you are following are following back and this article shows how to do it.
When developing a web page with accessibilty in mind, access keys are usually a consideration especially when part of the brief is to “make this site as accessible as possible” . Access keys were brought in by the W3C in 1999 to allow people with blindness or mobility problems who would have difficulty in using a mouse the option to press a key shortcut on their keyboard to select a link.