what's the speed limit .....

What's the speed limit in the far left lane on the highway? Everyone I know calls it the "speeding lane" and claims police will pull you over for going 65-70 mph in the left lane... But... The signs say 65 mph. Not "65 mph in 3 lanes, and bat outta hell in the far left lane". I've also seen cops pull people over in the left lane (unknown reason-- minus it being the end of the month) but people insist the left lane is "for" speeding 😒. What are your thoughts? I have a newer model car and I cannot tell I'm usually going 80mph. I remind myself to slow down, especially with it being deer season, and holidays and distracted drivers around me. I'd like to know what you think, what you know, and what you do on the highway.