Why it's bad
What to do
Non-compliant redistribution should be addressed by contacting the distributor in question and gently and politely noting their obligations under the license. Pointing to the Wikitravel:How to re-use Wikitravel guides page is a good way of showing them what to do and how to do it, and most people are happy to comply if asked nicely.
Borderline or unclear cases, cases that have not replied to contact attempts or cases that have rejected attempts to comply should be posted on the talk page.