Mutiny, rioting, protests - how to deal with them?

It seems to be a much more common trend for someone to start screaming about a protest or a riot, people group up, usually in front of security or bridge and the round severely deteriorates from there.

How is command / security supposed to deal with such an occurance and what kind of force/sentences can be used?

They can deploy flashes, flash grenades, tear gas grenades and use Stun batons to get one guy at a time.

If one security guard or high ranked crew member gets crit or dies then bring out shotguns before they open security doors

As what the person said above, I don’t tend to like to use shotguns, or bean bags on crew, even though they seem to get out of hand, you can always fax centcom and or ahelp it if it gets out of hand. Most riots tend to be against the rules but can be dispelled in game. 

Disabler/rubbers and stun baton them if you go into arrest them, just be careful they don’t slip and take your tools, if they make the arrest unsafe, by space law you can use lethal. 

I once arrested the same guy 5 times, after serving 5 minute sentences each time. I was given the okay by captain to just perma them because it was taking up a majority of sec’s time whilst we were having actual traitors act out. 

Good self control, me would have ended welding them into a locker

I’ve found understanding why people are rioting first is a good idea. Overall it would not help with the situation but it will help prevent it in the future. 
 

I often find smokes ineffective, people tend to turn on internals or just walk away and come back. The best thing to do is to scare them off, I like to do this by firing a couple shots into the wall. People would hear the shots not see me and start running in the fear of syndicate or being round removed. 
 

I know it’s kinda nrp to do a that in a since, but when the riot is the crew trying to kill hop because they said “Skibity toilet” over the intercom I don’t care much. The best way I find to solve something is to be a part of the problem some times, get into their mindset then find a solution.

To summarize what everyone else said, first of all try to figure out what started it and if there’s a way to settle things through talking it out. If not, you have non-lethals and riot gear for a reason. I’ve seen some riots get stopped by tossing a tear gas nade or two. If things get really out of hand, use lethals if you must.

There’s a few relevant crimes in Space Law you can reference, like the literal Rioting offense that’s 8 minutes. Don’t be afraid to perma any repeat offenders or severe cases. A lot of players tend to forget perma isn’t just for syndies.

Lastly, whether or not you’re able to resolve it IC, ahelp the situation and make sure you get the names of those involved just in case. Even if an admin doesn’t show up, it’s very helpful seeing certain characters pop up often in reports.