Should I give information to a past landlord about a tenant who owes a lot of back rent?

I assume you have a grudge and want some evens. That would be very interesting. If a past landlord wants to sue a past tenant, they have to have an address so that they can be served. I say why not. Deadbeats deserve what they get. . .and they are the ones that deserve to get it. . .

Landlords in many areas have an organization, and if there is one in your area, this is a good clearinghouse for exchanging references regarding tenants.

Are you suing your former tenant for back rent? Since you know where that tenant is, you can pursue the matter through the courts and have the marshal serve process on the tenant at that new address. The landlord will probably find out about service of process.

If this is not a former tenant of yours, but you have info for a landlord, you can write stating that you have info regarding tenant name's current whereabouts and to email you if he requires the info. If you were given as a reference or next of kin by the tenant and withhold relevant info, you might have a problem, so in such a case, definitely offer the info.

Woah! The word here that I locked onto is 'past'. Do you have a grudge issue going on here? I agree with the answer that suggested you wait to be asked before pitching in. This could well come back to haunt you. Back off!!

I would send it anonymously in case the tenant wants to get revenge on you, but sure, send it in.

If contacted, yes.

Sounds more like vengeance.

Yep, you get nothing out of it. It has nothing to do with you. I recommend you to get out of it.

Why? What do you get out of it?

If they don't ask you...then don't tell.