Can the Homeowner's Association do this?

I own a condo in a high rise Community and we have a board of directors. They have sent me a letter saying that I am in violation due to no Leasing Permit. In our community we have to obtain a permit to rent out condos.
I have a guest that comes into town occasionally and stays with me. They think this is a tenant. On the notice, they have indicated her first and last name, but there is NO other way they would know her name.
This guest does pay my cable bill, though.

Is it legal for the Association to call the cable company and find out who's name the account is under for my condo?? The whole building only uses 1 provider for cable and internet. Is this legal?? What else can they do in trying to figure out if I have a tenant..can they enter my unit or anything like that?

[annjd]

They can sue you in small claims and subpoena any evidence they want if it really is that critical to them.