Check for your clips, found lot of mine 

https://www.pond5.com/artist/blackboxguild#1/2063

I assume you contacted Pond5?

"Search Results: 692,465"

.....

Does Pond5 have a partner program with blackbox?

This is the BlackBox account. They are an amalgamation of tens of thousands of videographers.

My guess is that someone stole your video, then submitted via BlackBox.  I would suggest you identify half a dozen specific videos that you believe are yours, and then contact Blackbox about the problem.

I am pretty certain they will be more responsive than Pond5, and a lot more useful.  Pond5 would have the problem of deciding to cancel the entire BB account, and since it is their largest supplier at the moment, that is not likely.

BB, on the other hand, is one Honcho who is very visible on Facebook, and a few minions behind him.  Tell him of the problem, and he is likely to track it down fairly quickly. He can then delete the account of the offending member much more effectively than could Pond5.

You say you see it on SS too. Just another manifestation of the same, since BB supplies both.  Resolve this with BB, and it will automagically get resolved with all 5 of the largest video agencies.

Report to Pond5.  I hear when they get a report, they freeze the user's entire portfolio to investigate. 

I would be extremely surprised to hear Pond5, or any other agency, would freeze the entire BlackBox portfolio if they found a few cases of theft out of the hundreds of thousands of submitted clips.  Heck, we have already seen here that it is hard to get them to close down an account when it is a single person whose whole entire portfolio is composed of theft.

OTOH, contact BlackBox directly. They are far more likely to close down the account of the thief.  In so doing, you cut it off at the source, eliminating all 6 agencies that the thief's media is now being sent to.

And FWIW, I was a BB contributor (850+ clips there), but have soured on them. I no longer submit any new media to them, and use StockSubmitter instead for my multiple distribution.  Multiple reasons I have left BB, and I don't really want to go into detail on any of them in public. I do, however, heartily support StockSubmitter (or more accurately, MicroStock Plus, which is the cloud version of StockSubmitter, but is now in beta).  I am certainly willing to discuss why I like that mechanism -- but in a different thread, not as a sub-thread diversion here...

I would be extremely surprised to hear Pond5, or any other agency, would freeze the entire BlackBox portfolio if they found a few cases of theft out of the hundreds of thousands of submitted clips.

I was told directly by a P5 representative at NAB this year that this, indeed, is their policy when a copyright or intellectual property violation is brought to their attention.  They say it has happened before (maybe not with Blackbox), but with your stuff being mixed in with so many other contributors (some of which are probably "bad hombres"), why risk it?

As far as P5 (or any other agency) is concerned, BB is one user with no individuality.  Sort of like the Borg.  One bad egg ruins it for all.

Plus, I bet even if BB terminates a violator on their end, removing their associated clips from all the agencies BB works with is probably a very daunting task that I bet involves human intervention.  Sort of like removing only the blue sprinkles from an ice cream cone.

I was told directly by a P5 representative at NAB this year that this, indeed, is their policy when a copyright or intellectual property violation is brought to their attention. 

hmmm... Were you expecting them to say they ignore such reports??? 

Seriously, that is the standard game answer and I would be very surprised if every agency in the world has not memorized it for use when speaking to "the public" (or likely even shareholders).

Realistically... we have seen much different from people here that have tried to get such accounts pulled.

Now, you can tilt at windmills all you wish.  Personally I am more pragmatic, and look for the pressure point where the minimum effort on my part can create the largest change in the market.  Sorry if you have a stick up your tail about BB, but that is where the pressure point exists here.

Get them to remove the account, and you instantly remove it from 6 major agencies.  Not sure how much it will take to remove the existing stolen media, but you will at least prevent new media moving online through that mechanism.

Not sure about you, but I don't wait around and study my navel trying to find "The One Ring To Rule Them All" that will fix everything now and for all time.  Rather, I find what I can do (again with minimum effort) to solve a part of the problem.  I will then (if it seems important enough) move and try to solve other parts of the problem...