I think he meant he doesn't follow Snowden

I don't think so. Who was following Snowden before the leaks?

CBP has hassled me over having a book on Korean and a documentary about Hitler.

It's not necessarily racist if someone was overly nervous and hid friends, especially if they were non-Arab and notably Islamic (since Muslim isn't a race). Though the chance of a random CBP agent having a bad day probably dominates your threat profile unless.you're otherwise really notable.

If I was going to, say, China, I might hide friends that were pro-evangelizing their religion. Fortunately I don't use social media.