Following A Link

While browsing for cheap hotel rates, Alice notes a link from a hotel reservation site that's unknown to her to what is claimed to be a special promotion by the frequent flyer program that she collects miles in. Before following the link, Alice wants to be sure that it actually refers her to her frequent flyer program's web site, and nowhere else. She causes the link target to be displayed in her user agent's status bar; when she clicks the link, however, an onclick event leads to the execution of a script that redirects her elsewhere.

This use case could motivate looking into: