Tape on dustcovers

Hi. I was watching a program on TV earlier this evening, and there was an interview with a studio technician.

Over the mixing table there was a 3 way Genelec speaker on each side. I noticed that the dust caps on the woofers was covered with tape! The same tape you use when sealing a paper box. (The brown one, about 2" wide) The dust caps seems fine as far as I could see.

Anybody have any idea why this has been done?

Nobody has any idea of this?, Well, then I have to call the studio.