Cardiff Council is considering swapping black refuse bags for clear ones, in order to spot missed opportunities for recycling.
It's just one idea being considered as part of a green paper on recycling initiatives that'll be published in the summer.
The council says it must look at all opportunities to maximise recycling.
"It's a very very good way of finding out a lot of information about somebody" says Emma Carr, from Big Brother Watch.
"I think allowing people to see very very clearly who you are as a person when you may feel uncomfortable with that is certainly a step too far".