A lot of you probably already listen to RFC. Their weekly podcast is always a good listen IMO.

Recently they have released a couple of Minicasts on 3rd Party, IP, Copyright and Trademark where one the hosts of RFC talks with an Ex. Intellectual Property Lawyer on the matter.

Don't worry, they don't hate on 3rd party, but simply talk about the thin line 3rd party companies walk to get Transformer inspired robots into the very hungry for more hands of collectors, how these 3rd parties potentially get away with it and what Hasbro/Takara's obligations or concerns (if any) may be.

First one found here

and a follow up specifically talking about Tarn (from IDW), Reprolabels (toyhax) and Wikis here

I highly recommend any toy fan transformers or otherwise have a listen.