His introductory message is pleasant enough and he mentions one of your hobbies as an activity that he enjoys as well. His profile photos seem legit and his profile does not scream "Girl, you in danger".
So you reply to his initial message and a nice exchange begins...until after the fifth message when he starts trying to lock you down. You read the message in question and decide to spend a few hours offline. When you log back in, he has sent you two additional messages which seem to fault you for not responding quick enough.
A feeling of déjà vu flashes through you. This is supposed to be the pre "getting to know you phase" and this guy is already trying to jump ahead 5 spaces. You have definitely been here before. Everything is quick and romantic in the beginning. Six months in, after the newness has worn off, he is pacing around like a caged animal. The only thing keeping him around is pressure from his friends and family to settle down with someone like you. No, thanks to that ever again.
You decide to block him without explanation and go on with the rest of your day. Romantic crisis averted.