According to the report, published online on Monday, the DOJ may be looking broadly at ways that large telecom operators including AT&T and Verizon may be acting anticompetitively. Other issues include ways that operators restrict the kinds of services that can be offered on their networks, the Journal reported.

The DOJ does reveal when it is officially investigating a matter. It hasn't yet in this case, which could mean it is now considering whether to launch an official investigation.