All the quotes are from my LonelyPlanet:

Bulgaria:

Camping in the wild (ie outside a camping ground) is technically prohibited but normally accepted if you’re discreet and, most impor- tantly, do not build wood fires (which attract attention and damage the environment).

Greece:

Free (wild) camping is illegal, but the law is not always strictly enforced and some areas are more tolerant and renowned for it, espe- cially along the south coast. It is wise to ask around.

For Macedonia and Albania I could only find a general Western Balkans quote:

Camping in the wild is usually illegal; ask locals about the situation before you pitch your tent on a beach or in an open field.

All the quotes are from my LonelyPlanet:

Bulgaria:

Camping in the wild (ie outside a camping ground) is technically prohibited but normally accepted if you’re discreet and, most impor tantly, do not build wood fires (which attract attention and damage the environment).

Greece:

Free (wild) camping is illegal, but the law is not always strictly enforced and some areas are more tolerant and renowned for it, espe cially along the south coast. It is wise to ask around.

For Macedonia and Albania I could only find a general Western Balkans quote:

Camping in the wild is usually illegal; ask locals about the situation before you pitch your tent on a beach or in an open field.