The RIAA has nothing to do with those IP addresses!
- 192.168.*.*, 172.16.* to 172.31.*, 10.* (unicast private networks only)
- 169.254.* (unicast local network segment only)
- 224.* to 239.* (multicast addresses)
- 14.* (unicast special public data network not connected to the Internet)
- 127.* (unicast local host only addresses)
- 0.* and 255.* (broadcast addresses)
- 240.* to 239.* (reserved, undefined routing policy)
are private IP addresses used on LANs for local hosts, or addresses with special routing, and that are normally not routable on Internet (packets from or to these IPs should be blocked by all Internet core routers and by your ISPs).
For more information about these addresses and many others (which should not be seen as they are not allocated), look at "Bogon IPs" on this page:
http://www.completewhois.org/
If these addresses are found in Gnutella alt locations, they are either coming from your LAN directly, or will be unreachable on the Internet (LimeWire will display these addresses in Red, meaning that it can't reach them directly, but LimeWire may try to download from them using push requests, as they most often designate firewalled hosts which can't accept incoming connections).
Note that LimeWire has enhanced the detection of corrupted files. This does not mean that no corrupt file will be downloaded, but that distinct files shared with the same name or size or even the same SHA1 signature will not be mixed across sources. Recently, LimeWire integrated a new filter that allows grouping these distinct files more accurately. When a fragment download from any source completes, LimeWire checks that its content matches the expected signatures found in query hits.
Still it's impossible to determine if some people share corrupted files. One way for you to determine which files are probably not corrupted is that corrupted files rarely have more than 1 source, so a file from 2 sources is most probably not corrupted the same way on these two sources (or these hosts share the same corruption).