It is absolutely possible to watch Atlanta United FC games online without cable TV service. You don't need to pay those high priced cable bills just to watch them. Usually their games are on FS1, but that will change based on schedule or prime-time games.
I know this for a fact because I DO IT. It's virtually painless to setup and completely legal.
The MLS will attempt to blackout online streaming of Atlanta United FC games on if you are within the their home viewing area. This is a way for teams and local regional networks to retain their viewership numbers and by extension - their advertising dollars.
Luckily, there is a way for those of us that want to ditch Cable TV yet can't live without our Atlanta United FC games!!
ExpressVPN is a VPN service, which allows you to mask your home internet's IP address (this is how the teams determine if you are within their home "range" or not), which makes your home look like it is outside you home team's blackout area. ExpressVPN is my favorite service to get around regional blackouts. I have an account there, so I can personally vouch for it.
* If you want to consider a different VPN service, you can view a more complete list here.
When used for watching TV and your local sports teams, VPNs are not considered illegal in most countries (including the US) and anyone can use a VPN service to watch sports without fear of the police coming knocking at your door. The act of surfing the web or streaming shows through another IP is completely legal, and is something even the largest companies in the world do all the time. However, if you hide behind a VPN service to perform illegal activities, then you're of course violating the law - and we would never condone that.
If FS1 is part of your cable package, then your location is subject to blackouts. This happens because the cable companies want you to pay for one of their premium packages which includes FS1. If you circumvent this blackout with a VPN, then you are still supporting your team (you still end up watching their feed), you just won't be lining the Cable Provider's pockets with your hard earned money anymore. Here is a short list of sample locations that are absolutely within the blackout area:Atlanta, GA 30303