I mean, just to put another comment below, saying "your links are broken" must not necessarily solve the problem.
No point to add another comment, as ordinary users can't edit their comments anyway.
Two scenarios here:
- If the whole comment was based on the dead link flag it for moderator attention, choosing "other" and explaining the link is dead - if you have some time, look for mirror link or alternative place with same information and add to the flag report so the moderator might edit the comment instead of deleting it.
- If the comment is not all about the dead link, either let it be or like in the above scenario try looking for alternative live link and flag the comment asking to edit it with the new link.
Yes, I agree SO should implement a stale-link detector. URLs in answers is one thing, URLs in comments is another (and generally considered less significant, and more open to abuse). This feature-enhance request has many prior duplicates (some about answers, some about comments, some about both), check these out first before posting a duplicate feature-enhance request:
- Should SO check for stale (404) URLs?
- What to do when you find a bad link in an answer?
- Is it possible to automatically mark broken links?
- and I'm sure there are more
That's the easy part of the suggestion, there are several possibilities/opinions on what SO should do next, and beware that links should be automatically checked for (unintentional or intentional) malware:
- mark them as broken/ gray out/ icon to indicate broken
- some people think let any other high-rep user manually edit in a corrected (or substitute) link
- possibly notify the original poster (probably not a great idea)
- (my personal opinion) learn which sites have very ephemeral links and discourage people from posting links from those sites
It should be possible for users of a certain reputation to edit comments, this would help solve the issue of redundant links and also help fix spelling and grammar as with questions and answers to make the site more useful