I noticed a large number of pageviews from China / Russia / another location. Should I be worried?
PhotoDeck logs include these automated robots we don't know about. Having one's site crawled by automated robots is normal and is not necessarily an indicator of suspicious activity -- after all, the Internet is public. If image theft is a concern, make sure you have an adequate watermark on your images. Your private galleries and high-res files are always protected.
Can I block visits from country X?
No. It is not possible to reliably know where a visitor is located, and IP-address based filters only give a false sense of security. It is easy to spoof one's IP address / location, for example using a virtual private network (VPN), which is nowadays commonplace.