Many routes and boulders the world over feature holds that have been reinforced or stuck back in place with everything from sica to superglue but the practice is one that raises ethical questions for many in the climbing community.
In 2015, while working 'Gioia' (~V16/8C+) in Varazze, Italy, Daniel Woods and Dave Graham were unfortunate enough to break a foothold on the route. The decision of the problem's first ascensionist, Christian Core, to stick the hold back on the problem received significant backlash across the climbing world.
However, it soon emerged in a piece on 8a.nu that this decision was very much in keeping with both the ethics of Varazze and 'Gioia' itself. It transpired that the problem already featured five reinforced holds, a fact that came as something of a surprise to the wider community who may have been well aware of the practice on less well-known routes, but maybe didn't expect to find it on world-famous lines.
'Gioia' is notable as the world's first proposed V16/8C+ and while it will always be remarkable for its quality and difficulty, for many, its standing has been diminished somewhat by the knowledge that it is not as 'pure' a line as they may have previously assumed.