Raimund Karl of Bangor University in the UK has written a thought provoking piece entitled, On the Highway to Hell: Thoughts on the Unintended Consequences for Portable Antiquities of Section 11 (1) Austrian Denkmalschutzgesetz. See http://www.ngoe.at/publikationen/HEN_Karl.pdf
He concludes that a change in Austrian law has led metal detectorists to stop reporting finds they would otherwise report:
By effectively outlawing the use of metal detectors by members of the public to search for archaeological finds through § 11(1) DMSG, the many responsible amateur archaeologists who would be both willing to assist and interested in assisting with the protection of the archaeological heritage have been criminalized. This has completely removed many people’s motivation to report finds, intended to be strengthened by § 8 DMSG awarding a half share in the ownership of legally found and reported finds to the finder. As a result, most have practically stopped reporting any of their finds: this would, after all, be an at least implicit admission of having broken the law, resulting in the loss of any ownership rights to the finds according to § 400 ABGB, and possibly even inviting prosecution.
After reading his article, one might conclude that Professor Karl seems to be blessed with common sense that has detoured him away from the "highway to hell" that has been taken by some of his more ideological colleagues in the archaeological community.