Star Trek: 10 Things You Need To Know About Transporters
7. Transporters Can Be Used As Weapons
The transporter has a very dark capacity while remaining the easiest method of travel in Star Trek's universe. Once an area is unshielded, it can serve to pluck any living thing from its location - and beam them wherever the operator chooses. For example, there are several occasions in The Original Series when some poor Red Shirts stepped on the Transporter pad, only to find themselves floating in space moments later.
The transporter can be co-opted as well. In The Darkness And The Light, while Dax and Worf are attempting to beam a member of Kira's old resistance cell to their Runabout, the transporter pattern is scrambled. This is deliberate - the deranged Cardassian Silarin Prin had been systematically wiping out the Shakar cell. He hid a tiny pattern scrambler on the poor victim, which ended up killing her in a horrible fashion - all while Dax and Worf looked on, unable to stop it.
More recently, Seven Of Nine used the transporters aboard La Sirena to beam several neo-Borg Drones into the foundations of Chateau Picard, killing them instantly as they rematerialized with half of their bodies fused to the stone.