There are many issues in ethics for travelers to consider, especially when visiting developing countries.
In countries where wealth and education are less evenly distributed, there is a greater risk for exploitation of those who are unable to protect themselves. This could include “beneficiaries” of corrupt aid agencies (i.e. orphanages or community projects which do not actually help those that they are supposedly designed to help), indigenous people, and of course, animals.
It can be difficult to sort through foreign attractions and uncover what’s truly ethical and what’s not, especially in countries like Thailand where many clearly unethical practices are accepted as standard. Animal tourism in particular is huge in Thailand. If you go to Thailand without taking pictures with a tiger or riding an elephant, did you really even go?