When you use the ALT key actually you can't draw a vertical line on multiple lines and insert text. You also need already have copy a multiple line selection to be able to copy it on multiple line, editors such as Notepad++ or Visual Studio 2010 can insert text directly from the key board on multiple lines.

I think the insertion of text might be done only where there is some text, not on empty line. Or by using something like CTRL+ALT+Mouse drag to do a multiple vertical selection on many text blocks.