Friending people on Facebook

In a work or college class setting, after how many days/convos is it considered socially acceptable to ask for someone’s Facebook?
realsocailskills said:
I think that in most situations, you shouldn’t be asking someone for their Facebook. Generally speaking, the way to connect with someone on Facebook is to send them a friend request without mentioning it elsewhere. This lets them either friend you or not, depending on what they are comfortable with.
If you think that they might not know who you are, it can be a good idea to send a message with your friend request. Like “Hi, I’m in your physics class.”
If you can’t find someone on facebook, don’t ask. If someone is hard to find on Facebook, they have probably made it that way intentionally. If they want to be Facebook friends, they will send you a request. (The except is if you are both hard to find on Facebook and you are becoming friends. Then it’s ok to say something like “So, we’re both pretty hard to find on Facebook. Should we add each other?”)
Friending people who go to your school is usually ok, and unlikely to be seen as invasive. Most people will probably friend you back (although that’s their choice, and it’s important not to be pushy about it.)
In a professional setting, it is more complicated.
Facebook blurs relationship boundaries and causes you to find out all kinds of things you wouldn’t find out if you kept things to in-person interactions. You might be better off not knowing those things. You might be better off if some people don’t know those things about you, particularly people you work with professionally. 
Some people do not friend coworkers. Some people like to keep Facebook for personal friends and keep it as much out of their professional life as possible. Some people don’t like being easily contacted outside of work. In a work context, it might be better to err on the side of not friending people, unless you’re getting to the point of interacting with them outside of work.
Rule of thumb: If you have to work with someone, and your working relationship would be destroyed if you find out they have abhorrent political views or distasteful hobbies, you probably should not friend them on Facebook.
If your job is a campus job that you can change easily, or it’s a short-term internship, then it’s probably perfectly fine and even advisable to friend peers. That’s a good way to network and build relationships, and the risks are relatively low. If you find out something that undermines your ability to work together, you’ll probably be able to tolerate it in the short term knowing that the working relationship will end soon.
If someone is working for you, you probably shouldn’t send them a friend request unless they’re also in your social circles. If they want to be facebook friends, they will friend you. Even then, consider not accepting the request. If you’d really rather not know your employees’ political views or what they get up to when they’re not at work, you’re better off not seeing their Facebook posts.
Some people basically friend everyone who friends them or who they have ever connected with. That can be ok too, but if that’s your strategy, then it’s important to be a lot more careful about what you post on Facebook.
For instance, if you are friends with everyone on Facebook and you post a lot of controversial politics, it will undermine your ability to work with people who disagree with your views, even in completely apolitical contexts. If you are friends with everyone and post pictures of yourself partying, it will cause people to see you as less serious and professional.
There are many different strategies for using Facebook. They all have merits and downsides.
Facebook is a great way to connect with people and have conversations and plan things. When it works, it’s wonderful. But it can also cause far too much connection. In relationships that should be limited, be careful about using Facebook.
What do y'all think? How do you decide who to friend and manage boundaries on Facebook?