Scary Trip to Burlington

Hey so the scariest thing happened to me in the store Burlington, not sure what to think about it or even sure what happened . So I was just walking throughout the the store just like any other time I would go & I feel this guy walking oddly close to me with his phone out and so I go to the side get out of his way cause I wasn’t sure if I was walking slow , but instead of walking ahead of me he stops to look at something . So at this point I thought maybe he’s security or something and watching somebody but then i turn into an aisle and he also turns and is still really close to me with his phone out. So I just like stand away from him at this point and he puts his phone in his pocket and walks away .. am I over thinking this ? Or was he filming me walking .. I just want to know if this has happened to anyone and if so what did you guys do or alert someone