Have you recently done frequent withdrawals, or done high volume trades? They have limits on volume and frequency of trading that trigger a series of standard questions that they ask you. Sometimes they also ask for proof of where your Bitcoins came from in addition to the questions.
These quotes are from a two year old thread about their questions (KYC questionnaire).
Did anyone else receive such a message from support when they tried to withdraw money recently?
We received your withdrawal request. As your withdrawal request met some of our volume and frequency thresholds, we will have to kindly ask you to help us better understand the nature of your relationship with Bitstamp. In order to do so, we require that an additional KYC (know your customer) procedure is completed before we can proceed with the processing of your transfer.
We kindly ask you to answer the following KYC questionnaire:
1. How did you learn about Bitcoin?
2. The purpose of trading on Bitstamp?
3. What is the origin of the deposited Bitcoins? If mining, please specify your hardware specifications and submit a receipt or an invoice for your mining equipment.
4. When and how did you obtain your Bitcoins?
5. What is the reason for your activity - depositing BTC, selling, withdrawing?
6. What are your future plans and activities planned on our exchange?
7. Do you plan more of such withdrawals in the future? If yes, how many and why?
8. Which bank are you using? Please provide the complete address and SWIFT code.
We kindly ask you to submit your answers and documents in a reply to this ticket.
First of all, I exchanged money on Bitstamp exclusively since last spring. Withdrawals were less frequent during these last few months, but I had withdrawals both larger and smaller than the one I tried making now. I'm a verified customer with them.
Second, while some questions kinda sorta make sense, others are rather useless, redundant or impossible to address accurately. And some of their requests are downright audacious, not to mention grossly lacking respect to personal security. If I mine it's none of their goddamn business what the hell I mine with, what are the hardware specs and sure as hell they don't need to get invoices to every piece of hardware I mine with.
So, anyone else?
It's even worse than that: after I answered all those questions, they asked for records relating to the purchase of those bitcoins. MtGox doesn't have records from 2011, and BitInstant isn't even operating anymore!!
I'm not sure what kind of records they'd want for in-person trades with people I haven't spoken to since.
