Accessing FTP websites



Hi,
In the below link, i find ways to block FTP access and Enable FTP
access .

http://www.webmasterworld.com/forum40/954-1-10.htm


But, i would also like to know, what are the possible ways by which an
user will be able to log into those Blocked sites ???
And what are the ways to prevent them from doing it .... ???

Just to tighten security... !!

Thx in advance,
karthik bala guru

.