california bars employers from demanding social media info, post

Things that i learned:

• i didn't know that in california employers cant demand social media info
• i didn't know that know that employers were able to request social log in information before
• i didn't know that they used facebook and such to look up applicants for jobs

opinions: 

• i dont like how they could ask for you login info
• i kinda like how they could use facebook to look up applicants

why do employers want your log in info in the first place?