My phone is safer in my custody - it doesn't matter who I am giving it to, including YC founders/staff. Giving my phone to other people, regardless of who those people are, is an extraneous risk when compared to having it in my pocket on silent.

I'm sorry - but this is just bad personal opsec regardless of what event you're attending, or who you're rubbing elbows with. Sorry, but my opinion on this is different than yours.

So it's full of high-profile targets? Cool.