how much do you worry about copyright for funny pics sites

Sites like reddit have pictures from various places. I'm thinking of creating a site like that and I'm just doing my due diligence before I get started. Do they just contact you and ask you to take a pic down? Have they ever threatened to sue? Did they?
What if you just post a link to their site? What about the pics posted on upload sites? I don't believe those are public domain are they?

Person sends you a DMCA > You remove content. As long as you remove content you're fine.

Simple!

hmm.. so as long as I delete it upon request they can not do anything? What if they want to be a dick about it?

Go with your idea, All sites with user generated content is following the same policy.