The phrase "are often shared by" is correct and usable in written English.
It can be used to indicate that something is commonly distributed or communicated among a group of people or entities.
Example: "The findings of the research are often shared by various academic institutions to promote collaboration."
Alternatives: "are frequently communicated by" or "are commonly disseminated by".
(Elsewhere, postcodes are often shared by several buildings).
In the car industry a vehicle's main components, including steering, suspension and power train, are often shared by different models.
The episode supplied an unwelcome reminder that the area's transit corridors are often shared by freight operations, particularly during off-peak hours.
Yet Republican strategists believe they have an ace up their sleeves in the party's embrace of conservative social values that are often shared by many Hispanics, who are often deeply Roman Catholic and family-oriented.
There are other sensitivities in arid regions around the world where groundwater basins are often shared by unfriendly neighbors — India and Pakistan, Tunisia and Libya or Israel, Jordan, Lebanon, Syria and the Palestinian territories — that are prone to suspecting one another of excessive use of this shared resource.
We have tried to distinguish between fortunes that belong to individuals or nuclear families, and those that have been passed down through more than one branch of the family tree and are often shared by dozens of heirs.
The duality she expresses in her writing is often shared by others who have the condition.
This inclination toward separation of decent citizens from government is often shared by even the most well-meaning elected officials, who deliberately try to exclude the public from involvement in the governmental process.
At the same time, it's an issue where the more conservative, restrictionist position is often shared by a different bloc of swing voters: The kind of working class whites whose support Romney has been struggling (and struggling, and struggling) to win.
Today childrearing extends beyond the biological parents and is often shared by divorced parents, their new spouses and other family members.
For the use of urban space, the original residents attempted to improve the quality of their daily lives through small-scale transformations of privately owned outdoor spaces, which were often shared by their neighbors and other family members.
