It's wrong to use your co-worker's things without permission.
Tina works in an office and deals with a variety of sensitive documents.
Tina wants to shred some papers.
Tina gets her own paper shredder and uses it to shred her documents.
Tina uses one of her co-workers' personal paper shredders to shred the documents.
Tina's co-worker is able to shred his documents as well.
Tina's co-worker cannot shred his own sensitive documents in time.