Zhǎo fángzi de shíhou yào xiǎoxin, yǒuxiē zhōngjiè hěn kēngrén.
Be careful when you look for an apartment, some agents really rip people off.
Tips
usage
Extremely common in spoken complaint speech. The base verb 坑 (kēng, 'pit') means 'to dig a pit for someone to fall into' → to set up / cheat. 坑爹 (kēng diē, lit. 'cheats your dad') is a popular online intensifier with the same meaning.
memory
Picture digging a literal 坑 (pit) for someone to fall into, you 坑 them. The hapless target = 人 (rén).