Everything has pros and cons, so does online communication.
As far as I'm concerned, the pros lies in the convenience provided to family members, friends and lovers who are apart but have great eager to see and talk to each other. It alleviate our homesickness and thirst for expressing and accepting love.
Also it offers us a method to make acquaintance with more new friends from different places. You will never feel enough in having new friends, because it can help you get connected with more things and people in the world.
As for its cons, I think most of us have found that we today put excessive time on it which leads to less time on face to face communication and outdoor activities. We tend to rely on it to satisfy our needs for linking ourselves with others, but we are unaware of the limitation of it: although we can see others through some communication tools, but the time is limited and a lot of details can not be seen. So we won't know if our parents and friends are really going well when they say they do. And as you know, relationships requires physical interactions to get closer, but we can not hug and touch others through online communications.
Besides, it give us a illusion that we can solve all the things with a smart phone and so we have no need to go out if there are nothing necessary outside. Then we will no longer go out for exercise and enjoy the beautiful natural world. That will make us weak both physically and mentally.
But we can not say it's the fault of online communication, it's only a technological limitation. If there is really someone to blame, I think it is you, she, he and me that make this happen.
We should overcome the habit of staying at home alone during free time and walk out of the house to meet the one we love and get ourselves exposed to the natural world under sunlight.