That and the fact that your religion allows you to lie in order to put your victims off guard.
FROM Wikipedia:
In Shi’a Islam, taqiya is a form of religious lie, or a legal dispensation whereby a believing individual can deny his faith or commit otherwise illegal or blasphemous acts, specially while they are in fear or at risk of significant persecution.
A similar concept in Sunni Islam is known as idtirar ( “coercion”. A related concept is known as kitman “concealment; dissimulation by omission”. Also related is the concept of hiyal, legalistic deception practiced not necessarily in a religious context but to gain political or legalistic advantage.
This practice was emphasized in Shi’a Islam whereby adherents may conceal their religion when they are under threat, persecution, or compulsion.
Taqiyya was developed to protect Shi’ites who were usually in minority and under pressure, and Shi’a Muslims as the persecuted minority have taken recourse to dissimulation from the time of the mihna (persecution) under Al-Ma’mun in the 9th century, while the politically dominant Sunnites rarely found it necessary to resort to dissimulation.
In Sunni jurisprudence, denying faith under duress or other permissible reasons as per Islamic law is viewed “only at most permitted and not under all circumstances obligatory”.
However, there are many examples of practicing taqiyya among Sunnis where it was necessary.
In the Shi’a view, taqiyya is lawful in situations where there is overwhelming danger of loss of life or property and where no danger to religion would occur thereby.
Taqiyya has also been legitimised, particularly among Twelver Shia, in order to maintain Muslim unity and fraternity.