Landlords are extremely upset about a new website that shares information about the cost of renting an apartment.

The site, called, was launched in April with $18,000 in funding from several boroughs in Montreal.

The founders of the site said their goal is for tenants to share information about how much they are paying in rent.

"Any common people like me would like to know what is the price, like when they travel around Montreal would like to know what is the average here for a 4 1/2 or a 5 1/2?" said Luis Nobre, one of the site's founders.

He said armed with that information, tenants will have a better idea if a landlord's rates are reasonable or out-of-line for the neighbourhood.

Quebec's rental board makes suggestions about how much rent should be increased between tenants.

The board's Denis Miron said a tenant can even apply for a decrease if they find out after-the-fact that the rent increase was too high.

"Even though he already signed his lease, he has 10 days to apply to the Regie [du logement] to fix maybe a new rent," said Miron.

The website has been very successful and at times has crashed under the number of people searching it and adding information.

However landlords are now getting worried and allege the site is illegal.

Even though the cost of rent is always included in ads for apartments, Hans Brouillette of the landlords' association CORPIQ said collecting and sharing that information is against the law.

"It provides personal and confidential information about our leases, our rents, our incomes," said Brouillette.

"Nobody wants to have his income being provided on a public website."

Landlords also said there is no way to verify if the information posted is accurate, although the operators of say they are working to verify as much data as they can.

Brouillette also pointed out that landlords have the right to charge whatever the market will bear -- and that's it only fair to increase rent after renovating a space.

"In some cases there were renovations, in other cases the rent was much too low compared to the market," said Brouillette.

Lawyers for CORPIQ are tracking the data posted, but the association has yet to decide what, if any, legal action it will take.

About 1,500 tenants have posted the amount they pay in rent.