What is known to bypass LittleSnitch?

What apps are known to bypass LittleSnitch and get to the Internet without its approval? It seems to me I heard that Adobe apps and Filemaker do this. If so, how are they doing it?

Also, are there any known System connections, from software supplied by Apple with the system or for free, that make any Internet connections in such a way that they could connect without a rule in the Little Snitch rule list?

I ask these questions for both LS2 and LS3, just curious, how bullet-proof, is it really?

Thanks.