Bitcoin Sellers who Request Photo ID, is this safe?
Cryptocurrency companies generally require photo identification to protect the company. The legal concern of exchange of cryptocurrency is money laundering, and by requiring identity verification, you know who you're receiving currency from or giving it to. Of course, companies will also need to have procedures in place to detect identity fraud. Some exchanges will require you to provide a picture of yourself holding your photo identification.

As for whether it is safe or not, it really depends on how trustworthy people believe the company is.