Jakub Korab of the Dublin Java users group raises some good arguments about agencies updating a CV before submitting it to an employer.

The logic being that the agency does not want the employer to contact me later on without them involved. While I appreciate the logic behind the practice, and have no problem with submitting a resume without contact details, I take objection to it……
Pasting an agency logo onto my CV without my permission is at the very least undesirable. I do not work through any given recruitment agency before a contract is signed, and do not wish to be represented as such.

As a result Jakub has decided to only distribute his CV in pdf format.  I did have my CV in pdf format in the past but changed it back to word format as some agencies would only except this format.

I have never had a problem with agencies removing my contact details from my CV but he makes a very important point about turning up for an interview and seeing a CV representing you badly formated. The post is well worth a read.