The anticompetitive schemes they engage in are so complicated and require so much background context that it’s basically impossible to explain to even subject matter experts, much less the casual reader.
Don't define markets and estimate shares... For example, a field like advertising sweeps worldwide, and includes lots of different products and services. Defining a "market" more narrowly, or even defining one at all, can create issues if economists aren't involved. There's no problem with referring to a "market segment,'' "sector," "business/' etc., but just try and avoid defining the "market" for what we offer. Similarly, estimating "market share" is complicated, and it implies a defined market, so guessing or approximating isn't very reliable.
If you want to keep a secret, you must also hide it from yourself.