I agree with the comments about legal action being impractical.  Not because of the fetish nature of the clips, but rather, hiring attorneys is not practical for a small organization, and the expenditure will be much greater than the return.  Big outfits like the music producers do not hire attorneys because they have “money to burn.”  Big companies don’t like spending money without a return, either, but for them, spending some money on this makes sense because their total volume of losses is so massive.  If all tickling producers were one company, that company would have large total losses as well, but even then I doubt that the economics would make sense.  Keep in mind that while the music industry spends a lot to minimize the problem and stem the tide somewhat, it remains a huge one for them.  Most high-schoolers seem to have 1000 songs on their ipods.  They did not each spend $1.25 per song, or $1,250!
I don’t pretend to know the answer, from the producer’s standpoint.  The one comforting observation I might offer is, the nature of the internet (easy worldwide and anonymous access) provides both the blessing that makes clip production possible and the curse that allows people to steal.    Tough as it is to be a producer under the status quo, it was more difficult, and for the most part, impossible, before the internet was available for use by most people.
From a consumer’s standpoint, we should all remind ourselves that stealing clips is stealing.  No one who does so should comfort themselves with the usual trite excuses (the seller makes a lot of money anyway, the tttony excuse that the seller is bad because he thinks that what they sell is bad so stealing from them is ok, etc.)  Excuses for stealing and for those who steal are lame.