The UC Davis article is a good read. Just updated my Macbook Pro from Snow Leopard to Mountain Lion and am trying to solve the compatibility issues as I discover them. Smithmicro wrote some good programs that they no longer support past Snow Leopard: Internet Cleanup containing Network Spy Alert among other useful programs.
Hoping someone else has written similar programs that are Mountain Lion compatible or can relate a workaround so I can continue using Internet Cleanup.
The "Answer "in this thread is about the best advice you're going to get.
Ignore pretty much anything else that is said on this topic, especially if the the source happens to also be a vendor of paid software.
The reason they no longer support them is that they are no longer necessary. Since SL 10.6 Apple has introduced Xprotect.
Read Thomas Reed the part on How Mac protects you
and the rest of his article Dominic links to.
Thanks for the link.
The Net Blockade function of Network Spy Alert was quite handy in stopping additional and apparently unnecessary connections that were requested after a page (or app) had loaded.
Another concern: WiFi takes about 5 minutes to locate and ID local WiFi networks; was nearly instantaneous before under Snow Leopard. Internet Cleanup is still installed but the Net Blockade and Device Sentry functions are turned off - the Internet File Finder cleaning app still works and is quite useful.
From time to time a warning window pops up stating to 'uninstall kernel extensions' relating to the program or the warnings will continue. I'm not being allowed to copy and paste the warning for some reason.