How do I avoid copyright issues on Tumblr?

Hi, I'm new to Tumblr and was thinking about starting a classy/gentleman block there and was wondering what issues I might face when reposing and uploading.

Can I get sued for re blogging pictures from other blogs?

What's the most efficient way of getting followers fast and safe?

I first though of using a photoripper but then read about copyright issues so that's why I'm asking.

Cheers!

No you won't get sued from reblogging.
Best way to get followers fast and safe is from following/liking and don't forget to queue good pictures with very important "tags" that relates in your niche
If you're really afraid, just place a sentence in the description of your blog that these are not my photos blahblahblah if you get what i'm saying.

Worst case scenario you get banned or asked to take something down. Don't post any of your personal information if you are worried about it.

You'll be hard pressed to find a Tumblr account that did not post photos they do not have the copyright for.