A bank can provide a level of security that the average person cannot provide themselves. Perhaps the same will be true for crypto currencies at some point. The average person will not have the skill set required to secure their own money while still maintaining the ability to use it conveniently, and so online banks will be entrusted to keep the money.
Burento writes "The virus has two variants Troj/Pirlames-A and Troj/Pirlames-B, masquerades as a screensaver and attacks files with these popular extensions — EXE, BAT, CMD, INI, ASP, HTM, HTML, PHP, CLASS, JAVA, DBX, EML, MBX, TBB, WAB, HLP, TXT, MP3, XLS, LOG, BMP — overwriting them with images of comic book character Ayu Tsukimiya. http://www.weirdasianews.com/2007/03/01/p2p-virus