Anger at 'absolute filth' in Scotland's mountains
Separate incidents of littering in the Cairngorms have prompted angry responses on social media.
The Mountaineering Council of Scotland has shared a YouTube clip of a hillwalker describing rubbish left in a remote location as "absolute filth".
And one of two volunteers who looks after Corrour Bothy in the Lairig Ghru has told of taking four hours to sort through and burn waste left there.
Neil Reid said hillwalkers have to be willing to pick up litter they find.
In the YouTube clip the hillwalker shows a plastic bag of half empty yoghurt pots and other food waste he found in a "very remote spot in the Cairngorms".
The Mountaineering Council of Scotland has shared the clip on Twitter.
In a blog on UKHillwalking.com, Mr Reid said it was not good enough to "tut" at the recklessness of others and said people should be prepared to collect rubbish they find and take it off the hills.
But he added that setting up some form of "bothy vigilante patrol" as suggested by one of the blog's followers was not an answer.
Both the YouTube clip and blog feature strong language, with both the hillwalker and Mr Reid expressing frustration about the waste being left in the Cairngorms.
Mr Reid signed off his blog saying: "It's not enough just not leaving your own rubbish; let's make it socially unacceptable for others to leave rubbish too.
"And if they go ahead and leave it anyway? Then just pick it up.
"Whether the real culprit is there or not. Pick it up and become part of the answer, or turn a blind eye and be part of the problem. It's that simple."
Littering has been a problem in Scotland's hills, and other upland areas of the UK.
A total of 88 people were involved in the clean up of Ben Nevis in Scotland, Snowdon in Wales and England's Scafell Pike.
More than 24 stone (153kg) of litter was collected from Ben Nevis alone.
RSPB Scotland and National Trust for Scotland raised concerns in October last year that the faeces on Ben Macdui posed a potential health risk.
The RSPB said there had been no incidents of irresponsible toileting detected since last year.
The two charities own the 4,295ft (1,309m) mountain.