The idea of legalizing the world's oldest profession has often been a controversial one among many. When considering shock value and what approach you will take, you may want to attempt arguing for the legalization of prostitution; however, you can also consider arguing against it. When arguing for the legalization of prostitution, you might include information or statistics about its frequency, make the point that it legalization could allow it to be taxed or argue that legalization will promote public health since prostitutes will be given access to health care and disease testing. If arguing against it, you might suggest that prostitution still serves to oppress and exploit women and will promote an increase in sex trafficking.
Some people may be unaware of the specific and visceral details of animal treatment under factory farming, and a speech on this subject is sure to raise a few eyebrows. You can achieve a shocking speech if you argue against factory farming and elaborate on the spread of disease, animal cruelty and environmental pollution intrinsic to this practice. For instance, many people would be shocked to learn that their eggs come from hens that are kept in cages 16-inches wide for their entire lives or that the pork we eat often comes from pigs in environments rife with diseases such as cholera. Citing specific examples of factory farms investigated for disease, cruelty or pollution will add power to your argument.
Regarding equal marriage rights for homosexuals and heterosexuals, the shock value may depend on the approach you take. For instance, one approach may involving arguing against equal marriage rights by citing the religious reasons against marriage stated in the Bible or arguing that children raised in same-sex marriages would be likely to suffer gender disorders. If arguing for equal marriage rights, you could cite some positive benefits such as the possibility of increasing adoptions or the issue of minority discrimination.
The legalization of assisted suicide has long been a controversial issue, and in a mixed audience either side of the argument has the potential to be shocking. When arguing for it, you can note that individuals should have the right to choose when to end their lives and that they should not be forced to suffer unduly. When arguing against it, you can mention the immorality of taking any life or the hypothetical ethical issue of the potential for abuse, as people without adequate finances are sometimes pressured to choose death. Including specific examples about people who have chosen assisted suicide or who have decided against it can help strengthen your argument.