At my work the boss installed a camera with audio recording I live in Illinois

Question

Not one of the workers in the office new about this. He went as far as to tape over the lights so you could not see them. When confronted about this he said he did not know where it came from. He said maybe the fire department snuck across while we were gone and installed it.  He later admitted he did it and took it down

Cynthia Pietrucha · Answer

My answer - NOT legal advice:  This answer might surprise you, but this is okay to do in Illinois. In one of my Illinois jobs, I found out my boss was secretly listening to my telephone calls. Shady but not illegal. Telephone and video monitoring (and email monitoring) in Illinois workplaces is legal - as long as you're not in a private place at work.  
 
Generally, video surveillance is legal in Illinois as long as all parties consent. What does consent mean? It means that all recorded parties have given permission. But there are also limits to this. The all-party consent rule only applies where a person can reasonably expect privacy. Would you reasonably expect privacy walking down the sidewalk? At a baseball game? In a school cafeteria? In a bar? In a hotel room? At work? 
 
At your Illinois workplace, your employer can install video cameras and secretly videotape you as long as it's vital to the company’s operations.  If confronted, all the employee has to do is say the reason for the video surveillance was more important and vital to business operations than the worker's expectation to privacy.  
 
Where in your workplace would video surveillance be illegal?

Cynthia Pietrucha · Answer

At your Illinois workplace, your employer can install video cameras and secretly videotape you as long as it's vital to the company’s operations.  If confronted, the *employer can say the reason for the video surveillance was more important and vital to business operations than the worker's expectation to privacy.  
 
Where in your workplace would video surveillance be illegal? 
 Bathroom 
If you travel, in the hotel bedroom. 
 If you change clothes at work, in the locker room.  
 
See also: https://www.ilga.gov/legislation/ilcs/fulltext.asp?DocName=072000050K26-4#:~:text=Sec.,changing%20room%2C%20or%20hotel%20bedroom. 
720 ILCS 5/26-4) (from Ch. 38, par. 26-4) 
    Sec. 26-4. Unauthorized video recording and live video transmission. 
    (a) It is unlawful for any person to knowingly make a video record or transmit live video of another person without that person's consent in a restroom, tanning bed, tanning salon, locker room, changing room, or hotel bedroom.

Q: At my work the boss installed a camera with audio recording I live in Illinois