You can get intel data packages from scans at planetary facilities, these can be sold via the contacts section at space stations. Barnacles can also be scanned and the data sold. Here is a list of popular barnacle locations
Merope 5 C
-26.3515, -156.4056
Pleiades Sector JC-U b3-2 1
-57.8318, 107.4311
-0.9981, 25.85
2.4138, 23.5577
9.34, 22.49
19.25, 92.09
20.1833, 86.7352
21.3348, 91.9834
21.6104, 89.0181
21.93, 96.98
23.16, 94.07
25.3363, 25.5291
Pleiades Sector JC-U b3-2 2
13, 18.24
49.5347, 102.0792
49.7519, 102.161
49.7498, 102.7589
49.9075, 102.7141
59.4, -59.7
60.4, -51.8
Pleione 11 A
0.8248, 176.5619
2.3189, 177.2434
Thanks and credit to Patau82 on the frontier forums for these locations.