Running a regular node is fine as you're routing encrypted information for the Tor network - your unlikely to get any hassle although check your countries laws on crypto first.

Running an exit node may be a different story. You could get false DMCA takedown notices or get charged with someone else's crime. Think of it this way; you're running an open proxy. Uses of Tor can send any traffic through your connection. That being said, some ISPs are ok with it, others won't tolerate it.

I suggest you checkout https://blog.torproject.org/running-exit-node if your really serious about running an exit node.