literately malfunction token. The problem is the token can only 'buy', but can't be sold. There are tricks in the selling code that only the owner (scammer) can sell. Outside people can only buy but never sell successfully. The scammers create the pairing pool using their token, then buy it to create an up-shooting curve. They will come back later to collect all ETHs leaving the garbage tokens stuck in tricked buyer's account.
Obviously you are talking about rug pulling which is easily the biggest issue being faced by the current projects and new projects being listed at instant swap exchanges like uniswap where liquidity is controlled totally by the team and being a dex anyone can take advantage and i think uniswap needs to come up with a way out.