Do more spies = greater chance of detecting enemy spy activity?

Also, is it a local effect, or just the total number of spies you control?

this is all just as far as i know.

1. no, they don't
and a security bureau obsoletes a spy in that city

2. local, on a per tile basis
the EP are global.

So there's no reason to have more than one spy in a city or tile, and no reason to have any in a city if there's a Security Bureau there?

Also, does the amount of espionage points being produced affect CE efforts at all, or are they just used to "buy" spy missions?

See this thread (http://forums.civfanatics.com/showthread.php?t=247719) for an in-depth look.

Enigma256 is correct.

The more EP you've produced, the higher the probability of finding foreign spies. It doesn't matter who those points went against.

You are also correct with your statements about spies in tiles.

Thanks.

also, it's ok to have the spies asleep, right?

Thanks.

also, it's ok to have the spies asleep, right?

It looks like they will help detect other spies on the plot they end their turn in. I don't think anything else matters.