We have computers on every desk, and in the office we have software that can monitor what students are on.(they know this) I have shut the computers down while other instructors are teaching because the students have been doing everything from searching dating websites to watching movies.
I know that with my students that by the time I can walk around to see what they are looking at on the computer they close the page. I also found that besides for every once and awhile where someone would look something up for the class that students don't do anything educational on the computers. SO, next semester the computers will be unplugged except for times that we are taking a test.
You put computers on every desk and actually expect students to listen to the lecture?
Fail.
I have never seen a university lecture hall in any country that actually had a computer at the desk.
So you waste money on software and man hours to police student computer activity?
Why not take the computers and put them somewhere other than where you lecture?
If you don't have enough space, then your program needs to expand or ditch the computers and make the students use the ones at the library.