Possible Duplicate:
Why do I get exactly the same comment by different users for my link-only answer?
Is there a new policy being enforced on Link-Only answers in SO?
Over the last 24-hours I've noticed a number of my own Link-Only answers being commented (with boilerplate comment "While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes.") and downvoted (by a number of different users) when they contain only a link... in these cases, a generic link to the PHP documentation for the appropriate function that the OP is asking for.
In all cases, they're answers that I provided 15 or more months ago, not to topical or current questions.
It feels very much as though people are systematically going through old questions actively looking for link-only answers and "boilerplate" commenting/downvoting them.