In reply to whenry:
Over enthusiastic gardening is quite a mild term for some of what went on.
I personally saw "X" with a PICK AND SHOVEL clipped to his harness as he abbed off to "clean" one route at The Yat.
I watched as he unclipped the Pick, and used it, road worker style, to remove "loose" boulders along with earth/undergrowth.
Then one loosened boulder, the size of a small TV, released from its home, went down the hillside, between the trees, bounced into the middle of a hotel car park, over the other side, and into the river (where the canoeists were !).
At this point the rest of us distanced ourselves from the miscreant (who I'm sure some people on this forum can identify but I won't - at least not publicly).
Luckily no cars or canoeists were hurt in the process.
Now I wish to underline that this was around 40 years ago, and I'm led to believe that the culprit ("X") no longer lives in this country.