Western Sharia is the practise of making purely religious, moral or other faith-based opinions into secular law.
Sharia is specifically tied to Islam, whereas Western Sharia describes the way Westerners turn their own faith-based morals into law.
Many Westerners are critical when Muslims practise Sharia, but Islam, at least, is very explicit when doing this. In the West similar cases often go unnoticed because we lacks a dedicated term to describe the phenomenon.
Western Sharia is most visible in the cases where it is a victimless crime and/or the problem displays evidence of heavy social construction (cf. Social Constructivism).
Thus, a law motivated by Western Sharia will often be several steps removed from objective reality, e.g. the laws may punish people for behavior that has few, if any, observable negative effects, and the legislation may often seem like overkill. Simply, the problem is much more of a construction than something arrived at by examining the facts. Often the morals-turned-into-law may persist for decades or even centuries despite a clear lack of effectiveness.
1. The laws against cannabis is an example of Western Sharia. It's illegal to own or sell cannabis despite the fact that both seller and buyer freely consent to the trade being made, and despite the fact that the science on cannabis clearly shows that cannabis is a relatively safe medicine and recreational drug (compared to e.g. over-the-counter painkillers and alcohol).
2. Bigamy qualifies as Western Sharia: despite being victimless, voluntary and confined to a very, very small minority of sub cultures in the West is is often a punishable offense to have either two wives or two husbands.
3. Western Sharia also prohibits prostitution. Even though the seller and buyer are in mutual agreement about the trade, and even though most research shows that heavy criminalization tends to aggravate the harms done to the prostitutes, many countries continue to criminalize either the prostitute and/or the customer.
4. Laws against selling sex toys were effective in Texas into 2007/2008, but such a law is not an example of a rational ban on something factually dangerous or damaging, hence it is pure Western Sharia.
5. The laws against pecific types of sex, e.g. oral or anal, are really laws aimed at homosexuals for no other reason than moral outrage at the very concept of homosexuality. As such it is an example of Western Sharia.