From a legal standpoint, the downloading or distribution of PS2 BIOS files over the internet constitutes copyright infringement. Sony Computer Entertainment holds the copyright to the system software.
— To legally run PS2 games on a PC emulator (like PCSX2), users must dump the BIOS from their own personal PlayStation 2 console. scph70012biosv12usa200bin full
If you obtained it from an untrusted source: From a legal standpoint, the downloading or distribution