admin“ça craint” is a colloquial expression used quite commonly by French people. It either means “it sucks” or “it’s dangerous”. Look at the 2 examples below.
- Je n’ai pas envie d’y aller, ça craint ! I don’t want to go there, it sucks !
- Ne sors pas tard le soir, ça craint ! Don’t go out late at night, it’s dangerous !