When portlet titles are very long, the portlet stretches beyond browser window.
1) Add some portlet to the page (for instance Calendar)
2) Click on wrench -> Look and Feel
3) Select "Use Custom Title"
4) Select "Show Borders" -> No
5) Input very long title in "Portlet Title" input field (for instance 200 characters long).
7) Refresh page
The request is to be able to set a character limit for this titles. Otherwise, the title could get very long and limit usability - forcing users to scroll to the right to access the configuration menu for portlets, not seeing all the portlet data etc.