Everyone always gets so excited over this. "Holy cow guys, be careful! The FCC will pwn you forever if you even think about running this code!" A cell tower is

Everyone always gets so excited over this. "Holy cow guys, be careful! The FCC will pwn you forever if you even think about running this code!" A cell tower is elevated, outdoors, transmits +10 W, and runs 24/7. Your BladeRF is likely to be indoors at ground level, has an output power of about 10 mW. You aren't going to get very far with that. You'll likely have problems detecting the signal over 100 meters, much less connecting and using it. It may be illegal, but if you aren't causing interference you'll have a hard time getting caught. That being said, yes. Check your local laws. If you do cause a problem and it's tracked down to you, expect to have some serious legal issues.