Sheikh Muhammad Muhammad Sâlim `Abd al-Wadûd
Taking people to places where lawful and unlawful activities are both possible – like a restaurant, a hotel, or the general marketplace – is perfectly lawful. You are not obliged to ask them what they are going to eat and drink at the restaurant.
This is a matter about which there is general agreement.
Scholars differ regarding taxicab drivers taking passengers to places where they will certainly be carrying out predominantly unlawful activities. Such places include bars, nightclubs, and known brothels. Many scholars deem this prohibited, since it is helping people in sin and iniquity.
Allah says: “Help ye one another in righteousness and piety but do not help one another in sin and rancor. Fear Allah: for Allah is strict in punishment.” [Sûrah al-Mâ’idah: 2]
However, even in these cases, if taxicab drivers are prohibited from refusing passengers by law or by company regulations, or due to the negative feelings against Muslims that refusing passengers might engender in society, then it will be permissible to take all passengers wherever they want to go.
This is because a taxicab driver’s work is basically lawful in and of itself. Indeed, the driver is providing people with an essential service. If either the law or circumstances prohibit drivers from discriminating against passengers, this does not mean that Muslims should be barred from an essentially lawful and useful profession.
And Allah knows best.
Source: Islam Today