People can easily lie
You cannot trust anyone online. A person could easily lie about his looks, age, financial resources, and many other things, which could mislead you if you trust them fully. (See Why do people lie?)
Probability of fake account is really high
Some people create their accounts in someone else’s name. This may prove out to be very dangerous if you provide your information to those people. (See Why do some people create fake social network profiles?)
A friend could become an enemy easily
As face to face interactions lacks when you have online conversations, your friend can quickly back off without letting you know the reason and turn into an enemy.
Looking for a victim
Some people have bad intentions, and they may be looking for a person they can easily target. If you are that soft target, they may bully, criticize, or use unfriendly comments. These people could be anyone, including spammers, hackers, or even rapists.
A false sense of comfort
It gives a false sense of comfort as we think that the people we are talking to online are trustworthy. However, we cannot develop an accurate judgment about their good and bad habits as we have not met them in real.
Friends could disappear abruptly
There is no certainty as friends can effortlessly come but more easily go over the web. The reason is that in online relationships, no secure connection is formed. It might be hurtful for you if you are too sensitive.
Getting exposed to inappropriate stuff
You can easily be deceived by a person whom you are talking to online. If you are a child or belong to a younger age group, you may think that you are talking to someone of your age group because that person has told you so. However, in reality, they may be adults, and they may disguise you as they might make you experience immoral stuff such as pornographic pictures or using profanity.
Damage the reputation
The sole reason for becoming friends with you for some people may be to deteriorate you from the inside out by damaging your reputation. What they do is they talk to you to collect information about you which they use to solve their awful purpose.
Spy on you
They can easily spy on you by using your information against you. First, they will try to collect all the crucial information you need, then spy on you and even blackmail you.
Lack of intimacy
Intimacy lacks with friends whom you meet on any social media platform. One of the biggest reasons is that online friendship is superficial. Even if you have ample online friends, you may feel lonely. Whereas, if you have very few friends, school, college, or society, you will never feel isolated and empty.