Thanks for replying. Definitely not official looking in any way, certainly not dressed as a council worker. Long grey hair wearing coat and warm clothing on a very warm morning. Appeared to be alone. The pieces of label are white, roughly finger nail size and cover the letters C and O always. All the bins in my opinion look to be as inconveniently placed as eachother. At a glance, I can't work out why she chose the ones she did and am wondering if it relates more to the properties than the bins themselves. Disturbing if this is casing. Will post a picture tomorrow but am more uneasy now.