How risky is it to give programmers access to Filezilla?

Hi,

I've been trying to get some coding work done on my WordPress theme files, and have been asked for my FileZilla login details. Is this necessary? What infomation can they access if I gave this to them?

I asked them to make the edits and send me the files to upload myself but this is the answer I was given, "I cant get the proper files to edit because wordpress has a very weird code and doesn't allow you to see everything." Doesn't make sense to me, could you give me some advice please?

Thank you

- Most hosts allow you to create ftp users that will let you specify what access rights a user is given.

- Most programmers won't code without direct access to the server because:
-- If there are any coding problems, they may not be able to fix the problem(s) without access. Some servers are set up different, and if they code on one server, it may not work on yours.

I'm generally wary about giving out ftp access to my servers, but I know it's needed for a programmer to efficiently do what I've contracted him to do, so my advice... create an FTP account specifically for this (or other programmers) that limit what they can do.

Also, before offering up the info and allowing them access, make a backup of your files.