There is definitely an increased need for home security these days. Sometimes, just having cameras on the exterior of a property is not enough. There may be blind spots and a burglar could still gain access without being seen. This is when indoor cameras are the best option. 
However, it has to be said, they are often not too attractive.
To avoid drawing attention to them, consider hanging pretty wallpaper in the room to draw the visitors eye away from the cameras. One of the best online options is the Wallpassion website which has a huge range of stylish wallpaper. The site has a useful category section to help narrow down the thousands of designs. A feature wall could be created at the opposite end of the room to the security camera, to distract any guests. It is better to be safe than sorry, and indoor security cameras can put your mind at ease.