It all depends on the specific dating site. Some of these sites cater to those with criminal backgrounds, while others are more stringent in their criteria and do not allow members with certain types of backgrounds. Generally speaking, the types of criminal backgrounds that are allowed on dating sites vary from site to site. In some cases, individuals may be able to find specifically tailored sites that fit their needs and preferences; for example, there may be a dating website specifically designed for those who have served time in prison or another form of correctional facility.