Just for context of what Biden's opinion was at the time, here is the 'meaningless sense' that appears to have originated in his bill, S-226, from 1991.
SEC. 2201. COOPERATION OF TELECOMMUNICATIONS PROVIDERS WITH LAW ENFORCEMENT.
It is the sense of Congress that providers of electronic communications services and manufacturers of electronic communications service equipment shall ensure that communications systems permit the government to obtain the plain text contents of voice, data, and other communications when appropriately authorized by law.
http://thomas.loc.gov/cgi-bin/query/F?c102:1:./temp/~c102sT9...: